The Experts below are selected from a list of 1097868 Experts worldwide ranked by ideXlab platform
Toshio Yamamoto - One of the best experts on this subject based on the ideXlab platform.
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Forced Oscillations of a rotating shaft with nonlinear spring characteristics and internal damping (1/2 order subharmonic Oscillations and entrainment)
Nonlinear Dynamics, 1993Co-Authors: Yukio Ishida, Toshio YamamotoAbstract:Nonlinear forced Oscillations of a rotating shaft with nonlinear spring characteristics and internal damping are studied. In particular, entrainment phenomena at the critical speeds of 1/2 order subharmonic Oscillations of forward and backward whirling modes are investigated. A self-excited Oscillation appears in the wide range above the major critical speed. The amplitude of this Oscillation reaches a limit value and then a self-sustained Oscillation occurs. In the vicinity of a 1/2 order subharmonic Oscillation of a forward whirling mode, a self-excited Oscillation is entrained by a subharmonic Oscillation. In the vicinity of a 1/2 order subharmonic Oscillation of a backward whirling mode, either a self-excited Oscillation or a subharmonic Oscillation occurs.
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Forced Oscillations of a rotating shaft with nonlinear spring characteristics and internal damping (1/2 order subharmonic Oscillations and entrainment)
Nonlinear Dynamics, 1993Co-Authors: Yukio Ishida, Toshio YamamotoAbstract:Nonlinear forced Oscillations of a rotating shaft with nonlinear spring characteristics and internal damping are studied. In particular, entrainment phenomena at the critical speeds of 1/2 order subharmonic Oscillations of forward and backward whirling modes are investigated. A self-excited Oscillation appears in the wide range above the major critical speed. The amplitude of this Oscillation reaches a limit value and then a self-sustained Oscillation occurs. In the vicinity of a 1/2 order subharmonic Oscillation of a forward whirling mode, a self-excited Oscillation is entrained by a subharmonic Oscillation. In the vicinity of a 1/2 order subharmonic Oscillation of a backward whirling mode, either a self-excited Oscillation or a subharmonic Oscillation occurs. Experiments were made by an elastic rotating shaft with a disc. Nonlinearity in its restoring force was due to an angular clearance of a bearing and internal damping was due to friction between the shaft and an inner ring of the bearing. A self-excited Oscillation was observed in the range above the major critical speed and this self-excited Oscillation was entrained by a 1/2 order subharmonic Oscillation of a forward whirling mode.
Yukio Ishida - One of the best experts on this subject based on the ideXlab platform.
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Forced Oscillations of a rotating shaft with nonlinear spring characteristics and internal damping (1/2 order subharmonic Oscillations and entrainment)
Nonlinear Dynamics, 1993Co-Authors: Yukio Ishida, Toshio YamamotoAbstract:Nonlinear forced Oscillations of a rotating shaft with nonlinear spring characteristics and internal damping are studied. In particular, entrainment phenomena at the critical speeds of 1/2 order subharmonic Oscillations of forward and backward whirling modes are investigated. A self-excited Oscillation appears in the wide range above the major critical speed. The amplitude of this Oscillation reaches a limit value and then a self-sustained Oscillation occurs. In the vicinity of a 1/2 order subharmonic Oscillation of a forward whirling mode, a self-excited Oscillation is entrained by a subharmonic Oscillation. In the vicinity of a 1/2 order subharmonic Oscillation of a backward whirling mode, either a self-excited Oscillation or a subharmonic Oscillation occurs.
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Forced Oscillations of a rotating shaft with nonlinear spring characteristics and internal damping (1/2 order subharmonic Oscillations and entrainment)
Nonlinear Dynamics, 1993Co-Authors: Yukio Ishida, Toshio YamamotoAbstract:Nonlinear forced Oscillations of a rotating shaft with nonlinear spring characteristics and internal damping are studied. In particular, entrainment phenomena at the critical speeds of 1/2 order subharmonic Oscillations of forward and backward whirling modes are investigated. A self-excited Oscillation appears in the wide range above the major critical speed. The amplitude of this Oscillation reaches a limit value and then a self-sustained Oscillation occurs. In the vicinity of a 1/2 order subharmonic Oscillation of a forward whirling mode, a self-excited Oscillation is entrained by a subharmonic Oscillation. In the vicinity of a 1/2 order subharmonic Oscillation of a backward whirling mode, either a self-excited Oscillation or a subharmonic Oscillation occurs. Experiments were made by an elastic rotating shaft with a disc. Nonlinearity in its restoring force was due to an angular clearance of a bearing and internal damping was due to friction between the shaft and an inner ring of the bearing. A self-excited Oscillation was observed in the range above the major critical speed and this self-excited Oscillation was entrained by a 1/2 order subharmonic Oscillation of a forward whirling mode.
Huimin Yang - One of the best experts on this subject based on the ideXlab platform.
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Water Channels Are Involved in Stomatal Oscillations Encoded by Parameter-Specific Cytosolic Calcium Oscillations
Journal of Integrative Plant Biology, 2006Co-Authors: Huimin Yang, Gen-xuan Wang, Xiao-yan Zhang, Jianhua ZhangAbstract:Earlier studies have shown that various stimuli can induce specific cytosolic calcium ([Ca2+]cyt) Oscillations in guard cells and various Oscillations in stomatal apertures. Exactly how [Ca2+]cyt Oscillation signaling functions in stomatal Oscillation is not known. In the present study, the epidermis of broad bean (Vicia faba L.) was used and a rapid ion-exchange treatment with two shifting buffers differing in K+ and Ca2+ concentrations was applied. The treatment for five transients at a 10-min transient period induced clear and regular stomatal Oscillation. However, for other transient numbers and periods, the treatments induced some irregular Oscillations or even no obvious Oscillations in stomatal aperture. The results indicate that stomatal Oscillation is encoded by parameter-specific [Ca2+]cyt Oscillation: the parameters of [Ca2+]cyt Oscillation affected the occurrence rate and the parameters of stomatal Oscillation. The water channel inhibitor HgCl2 completely inhibited stomatal Oscillation and the inhibitory effect could be partially reversed by β-mercaptoethanol (an agent capable of reversing water channel inhibition by HgCl2). Other inhibitory treatments against ion transport (i.e. the application of LaCl3, EGTA, or tetraethylammonium chloride (TEACI)) weakly impaired stomatal Oscillation when the compounds were added after rapid ion-exchange treatment. If these compounds were added before rapid-ion exchange treatment, the inhibitory effect was much more apparent (except in the case of TEACI). The results of the present study suggest that water channels are involved in stomatal Oscillation as a downstream element of [Ca2+]cyt Oscillation signaling. (Managing editor: Wei Wang)
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Cytosolic calcium Oscillation signaling in guard cell
Plant Science, 2004Co-Authors: Huimin Yang, Xiao-yan Zhang, Gen-xuan WangAbstract:Abstract Calcium signaling has been established to play a very important role in stomatal movements. More and more attentions have now been focused on cytosolic calcium ([Ca 2+ ] cyt ) Oscillation in guard cell. It is still not clear how [Ca 2+ ] cyt Oscillation occurs and how it is decoded. Another point which attracted a lot of attentions is the relationship between the Oscillations in guard cell [Ca 2+ ] cyt and stomatal aperture. Recent data provide conclusive evidences that guard cell can decode complex calcium Oscillation signaling and that [Ca 2+ ] cyt Oscillation in guard cell may induce stomatal Oscillation. This short review provides an introduction to [Ca 2+ ] cyt Oscillations in guard cell, the way in which they are generated and the correlations between [Ca 2+ ] cyt Oscillation and stomatal movements, especially stomatal Oscillation. The review concludes with a discussion that how [Ca 2+ ] cyt Oscillations are encoded and decoded, and a postulation that water channels may be involved in stomatal Oscillation.
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The parameters of guard cell calcium Oscillation encodes stomatal Oscillation and closure in Vicia faba
Plant Science, 2004Co-Authors: Gen-xuan Wang, Ming Xin, Huimin YangAbstract:Oscillations in cytosolic calcium ([Ca2+]cyt) are an important component of Ca2+-based signal transduction cascades and have been proposed as necessary for stomatal closure. The research about the roles of individual [Ca2+]cyt Oscillations parameters in regulating stomatal closure have been touched, but there still have many problems remaining largely unknown. We systematically vary the [Ca2+]cyt Oscillation parameters in Vicia faba L. guard cells to investigate their roles in stomatal movements. [Ca2+]cyt Oscillations could induce synchronous stomatal Oscillations and regulate the short-term stomatal closure during the Oscillation. The direct effect of [Ca2+]cyt on the activity of aquaporin may be the main cause of the stomatal Oscillation induced by [Ca2+]cyt Oscillations. Stomatal dynamics indicate the long-term steady-state stomatal closure can be apparently elicited by optimal [Ca2+]cyt Oscillation transient numbers and periods. The stomata in different growing phases have the different responses to the same [Ca2+]cyt Oscillation parameters.
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Cytosolic calcium Oscillation may induce stomatal Oscillation in Vicia faba
Plant Science, 2003Co-Authors: Huimin Yang, Gen-xuan Wang, Xiao-yan Zhang, Yan LiAbstract:Abstract Whether guard cell cytosolic calcium ([Ca2+]cyt) Oscillation induced stomatal Oscillation was investigated in Vicia faba leaf. Extracellular Ca2+, ABA and H2O2 treatments induced stomata to close in a dose- and time-dependent way. Both steady-state and rapid exchange treatments could first induce a steep decrease in stomatal aperture and then significantly induce stomatal Oscillations at small apertures. Steady-state extracellular Ca2+ and ABA treatments caused obvious but small and irregular stomatal Oscillations, and the Oscillations lasted for shorter time, while steady-state H2O2 treatment induced no stomatal Oscillation. Intriguingly, rapid exchange treatments of high [K+] buffer and high [Ca2+] buffer or high [ABA] buffer induced significant, strong, regular and longer time stomatal Oscillations, while no Oscillation occurred under H2O2 treatment in the same procedure. It was likely that [Ca2+]cyt Oscillations induced by extracellular Ca2+ and ABA could induce stomatal Oscillations and stomatal Oscillations occurred at small apertures.
Gen-xuan Wang - One of the best experts on this subject based on the ideXlab platform.
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Water Channels Are Involved in Stomatal Oscillations Encoded by Parameter-Specific Cytosolic Calcium Oscillations
Journal of Integrative Plant Biology, 2006Co-Authors: Huimin Yang, Gen-xuan Wang, Xiao-yan Zhang, Jianhua ZhangAbstract:Earlier studies have shown that various stimuli can induce specific cytosolic calcium ([Ca2+]cyt) Oscillations in guard cells and various Oscillations in stomatal apertures. Exactly how [Ca2+]cyt Oscillation signaling functions in stomatal Oscillation is not known. In the present study, the epidermis of broad bean (Vicia faba L.) was used and a rapid ion-exchange treatment with two shifting buffers differing in K+ and Ca2+ concentrations was applied. The treatment for five transients at a 10-min transient period induced clear and regular stomatal Oscillation. However, for other transient numbers and periods, the treatments induced some irregular Oscillations or even no obvious Oscillations in stomatal aperture. The results indicate that stomatal Oscillation is encoded by parameter-specific [Ca2+]cyt Oscillation: the parameters of [Ca2+]cyt Oscillation affected the occurrence rate and the parameters of stomatal Oscillation. The water channel inhibitor HgCl2 completely inhibited stomatal Oscillation and the inhibitory effect could be partially reversed by β-mercaptoethanol (an agent capable of reversing water channel inhibition by HgCl2). Other inhibitory treatments against ion transport (i.e. the application of LaCl3, EGTA, or tetraethylammonium chloride (TEACI)) weakly impaired stomatal Oscillation when the compounds were added after rapid ion-exchange treatment. If these compounds were added before rapid-ion exchange treatment, the inhibitory effect was much more apparent (except in the case of TEACI). The results of the present study suggest that water channels are involved in stomatal Oscillation as a downstream element of [Ca2+]cyt Oscillation signaling. (Managing editor: Wei Wang)
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Cytosolic calcium Oscillation signaling in guard cell
Plant Science, 2004Co-Authors: Huimin Yang, Xiao-yan Zhang, Gen-xuan WangAbstract:Abstract Calcium signaling has been established to play a very important role in stomatal movements. More and more attentions have now been focused on cytosolic calcium ([Ca 2+ ] cyt ) Oscillation in guard cell. It is still not clear how [Ca 2+ ] cyt Oscillation occurs and how it is decoded. Another point which attracted a lot of attentions is the relationship between the Oscillations in guard cell [Ca 2+ ] cyt and stomatal aperture. Recent data provide conclusive evidences that guard cell can decode complex calcium Oscillation signaling and that [Ca 2+ ] cyt Oscillation in guard cell may induce stomatal Oscillation. This short review provides an introduction to [Ca 2+ ] cyt Oscillations in guard cell, the way in which they are generated and the correlations between [Ca 2+ ] cyt Oscillation and stomatal movements, especially stomatal Oscillation. The review concludes with a discussion that how [Ca 2+ ] cyt Oscillations are encoded and decoded, and a postulation that water channels may be involved in stomatal Oscillation.
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The parameters of guard cell calcium Oscillation encodes stomatal Oscillation and closure in Vicia faba
Plant Science, 2004Co-Authors: Gen-xuan Wang, Ming Xin, Huimin YangAbstract:Oscillations in cytosolic calcium ([Ca2+]cyt) are an important component of Ca2+-based signal transduction cascades and have been proposed as necessary for stomatal closure. The research about the roles of individual [Ca2+]cyt Oscillations parameters in regulating stomatal closure have been touched, but there still have many problems remaining largely unknown. We systematically vary the [Ca2+]cyt Oscillation parameters in Vicia faba L. guard cells to investigate their roles in stomatal movements. [Ca2+]cyt Oscillations could induce synchronous stomatal Oscillations and regulate the short-term stomatal closure during the Oscillation. The direct effect of [Ca2+]cyt on the activity of aquaporin may be the main cause of the stomatal Oscillation induced by [Ca2+]cyt Oscillations. Stomatal dynamics indicate the long-term steady-state stomatal closure can be apparently elicited by optimal [Ca2+]cyt Oscillation transient numbers and periods. The stomata in different growing phases have the different responses to the same [Ca2+]cyt Oscillation parameters.
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Cytosolic calcium Oscillation may induce stomatal Oscillation in Vicia faba
Plant Science, 2003Co-Authors: Huimin Yang, Gen-xuan Wang, Xiao-yan Zhang, Yan LiAbstract:Abstract Whether guard cell cytosolic calcium ([Ca2+]cyt) Oscillation induced stomatal Oscillation was investigated in Vicia faba leaf. Extracellular Ca2+, ABA and H2O2 treatments induced stomata to close in a dose- and time-dependent way. Both steady-state and rapid exchange treatments could first induce a steep decrease in stomatal aperture and then significantly induce stomatal Oscillations at small apertures. Steady-state extracellular Ca2+ and ABA treatments caused obvious but small and irregular stomatal Oscillations, and the Oscillations lasted for shorter time, while steady-state H2O2 treatment induced no stomatal Oscillation. Intriguingly, rapid exchange treatments of high [K+] buffer and high [Ca2+] buffer or high [ABA] buffer induced significant, strong, regular and longer time stomatal Oscillations, while no Oscillation occurred under H2O2 treatment in the same procedure. It was likely that [Ca2+]cyt Oscillations induced by extracellular Ca2+ and ABA could induce stomatal Oscillations and stomatal Oscillations occurred at small apertures.
Risto J Ilmoniemi - One of the best experts on this subject based on the ideXlab platform.
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eeg Oscillations and magnetically evoked motor potentials reflect motor system excitability in overlapping neuronal populations
Clinical Neurophysiology, 2010Co-Authors: Hanna Maki, Risto J IlmoniemiAbstract:Objective: To understand the relationship between neuronal excitability reflected by transcranial magnetic stimulation (TMS) evoked motor potentials (MEPs) and spontaneous Oscillation amplitude and phase. Methods: We combined spontaneous EEG measurement with motor cortex TMS and recorded MEP amplitudes from abductor digiti minimi (ADM). Results: Midrange-beta Oscillations over the stimulated left motor cortex were, on average, weaker before large- than small-amplitude MEPs. The phase of occipital midrange-beta Oscillations was related to the MEP amplitudes. Conclusions: The present results support the view that MEP and Rolandic beta Oscillation amplitudes are associated with motor cortical excitability. However, Oscillations seen in EEG reflect the excitability of a large population of cortical neurons, and MEP amplitude is affected also by spinal excitability and action potential desynchronization. Thus, MEP and EEG Oscillation amplitudes are not strongly correlated. In addition, even during rest, motor system excitability appears to be related to activity in occipital areas at frequency ranges associated with visuomotor processing. Significance: The ability of spontaneous Oscillations and MEPs to inform us about cortical excitability is clarified. For example, it is suggested that oscillatory activity at non-motor sites might be related to motor system excitability at rest.
