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The effect of tail shape on the maximum nondimensional amplitude, Amax, at ξ=0.75 and the nondimensional frequency of oscillations, f˜, for nose A; Λ=0.5 – comparison between theory and experiment. ... Consecutive frames showing the towed flexible cylinder executing a cycle of second-mode flexural oscillation with frequency f=1.58Hz at U=2.4m/s (flow direction: ↓). ... Consecutive frames showing the towed flexible cylinder with Λ=0.25, executing a cycle of essentially criss-crossing oscillations with frequency f=0.25Hz at U=0.3m/s (flow direction: ↓). ... Consecutive frames showing the towed flexible cylinder executing a cycle of essentially second-mode flexural oscillation (the third-mode oscillation not fully developed) with frequency f=1.88Hz at U=3.0m/s (flow direction: ↓). ... The effect of towrope length on the maximum nondimensional amplitude, Amax, at ξ=0.75 and the nondimensional frequency of oscillations, f˜ (nose A; tail A) – comparison between theory and experiment.
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Pharmacological modulation of spontaneous Ca2+ oscillations and effects of altered extracellular ionic milieu in Fluo-4 loaded differentiating chondrocytes of 2-day-old HDC. Representative confocal line-scan images and time courses of Fluo-4 fluorescence intensities are shown; horizontal and vertical calibrations are the same for all traces in panels (A)–(D). Horizontal lines under traces show the duration of treatments with pharmacons or altered extracellular ionic milieu. Acquisition of line-scan images started immediately after changing the bath solution on the cultures. Prior to that, normal functions were detected on each culture. (A) Spontaneous Ca2+ oscillations in normal ([Ca2+]e=1.8mM) Tyrode's solution. (B) After the non-selective cation channel-mediated Ca2+ entry blocker LaCl3 (500μM) and the store-operated Ca2+ entry and Ca2+ release-activated Ca2+ (CRAC) channel blocker YM-58483 (1μM) were applied in normal ([Ca2+]e=1.8mM) Tyrode's, Ca2+ oscillations ceased, although irregular fluctuations in basal cytosolic Ca2+ concentration remained detectable. (C) When the SERCA-blocker CPA (10μM) was co-administered with 500μM LaCl3 and 1μM YM-58483 in 1.8mM [Ca2+]e, Ca2+ oscillations were totally eliminated. (D) 3min after changing the bath solution to Ca2+-free Tyrode's, periodic oscillations could not be detected. Line-scan diagrams on panels (A)–(D) are representative data out of 4 independent experiments. ... Pooled data of Ca2+ oscillations gathered from series of X–Y images acquired from random visual fields of Fluo-4 loaded HDC on culturing days 1 and 2 with Zeiss LIVE 5 Laser Scanning Confocal Microscope. (A) Ratio of oscillating cells and frequency of repetitive Ca2+ transients on days 1 and 2 of culturing. Numbers above bars indicate the number of oscillating cells compared to all cells recorded. (B) Amplitude and full time at half maximum (FTHM) of Ca2+ oscillations in differentiating cells of HDC on culturing days 1 and 2. For both panels (A) and (B), while calculating the parameters of Ca2+ oscillations, only oscillating cells with round, chondroblast-like morphology were considered. Measurements were carried out on cultures from 4 independent experiments. Data represent mean±standard error of the mean (SEM). Numbers in parentheses above bars indicate the number of cells measured. Asterisks (*) mark significant differences (*Poscillating cells in 1- and 2-day-old HDC. ... Spontaneous Ca2+ oscillations in cells of HDC on day 2 of culturing. Prior to measurements, cells were loaded with Fluo-4-AM for 30min Ca2+ oscillations were observed without agonist stimulation in Tyrode's solution containing 1.8mM Ca2+ at room temperature. (A) Series of X–Y images were recorded from random visual fields of chondrifying cultures with Zeiss LIVE 5 Laser Scanning Confocal Microscope. These four representative frames were acquired at 6.5, 18.3, 29.6 and 54.4s during measurements. Arrows indicate differentiating chondrocytes with repetitive intracellular Ca2+ oscillations. (B) Time course of fluorescence intensities of the cells marked with arrows in panel (A). Fluo-4 fluorescence intensity values normalised to baseline fluorescence (F/F0) are plotted vs. time. Wide ranges of frequency and amplitude of oscillating cells were observed. ... Pooled data of Ca2+ oscillations obtained from series of X–Y images acquired from Fluo-4 loaded HDC in response to various treatments. Measurements were carried out with Zeiss LIVE 5 Laser Scanning Confocal Microscope. A total number of 500 images were recorded at each time point for each visual field; frame acquisition rate was 10s−1. (A) Percentage of oscillating cells before treatment (control), and 1, 3 or 5min after the application of bath solution containing 10μM nifedipine, or 500μM LaCl3 and 1μM YM-58483. Values were normalised to the untreated cells measured at 0min (control), and then at 1, 3 and 5min. Numbers in parentheses above bars show the number of cells measured. (B) Amplitude of Ca2+ oscillations, normalised to values of untreated control cells. Numbers in parentheses above bars represent the number of oscillating cells measured. (C) Frequency of Ca2+ oscillations normalised to the control. Numbers in parentheses above bars show the number of cells measured. For panels (A)–(C), oscillating cells with round morphology in the same random visual field were recorded at all four time points. Differentiating cartilage colonies were only used for a single measurement series and then were discarded. Graphs represent pooled data of 3 independent experiments, measuring random visual fields of 5 colonies for each treatment. Asterisks (*) mark significant differences (*P<0.05) between parameters of treated vs. control cells at respective time points. ... Refined model showing known components of Ca2+ homeostasis and signalling pathways that modulate Ca2+ oscillations in developing chondrocytes. Ca2+ can enter the cell via voltage-operated Ca2+ channels (VOCCs), P2X4 purinergic receptors, NMDA receptors or TRP channels; changes in resting membrane potential are mediated by voltage-gated K+ channels. ATP is secreted to the extracellular space via putative connexin 43 hemichannels. Activation of G-protein coupled P2Y purinergic receptors cause Ca2+-release from the endoplasmic reticulum (ER) via inositol-1,4,5-trisphosphate receptors (IP3R). Depletion of the Ca2+ stores cause aggregation of stromal interaction molecules (STIM1/STIM2), which are the Ca2+ sensors of the ER and trigger the opening of the store-operated Orai1 channels. Reuptake of Ca2+ to the ER is mediated by the sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA) and the Na+–Ca2+ exchanger (NCX). See text for details.
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A time course of glutamate-induced GFP-PKCγ translocation versus a time course of Ca2+ signals in hippocampal astrocytes. (a) The time course analysis of repetitive GFP-PKCγ translocations (green trace) compared to the time course of intracellular Ca2+ oscillations measured with Ca2+ Crimson (red trace) resulting from the addition of 100 μM glutamate (final concentration). These dual measurements were made by rapidly switching between TIRF-excited GFP images (excitation: 488 nm) and epifluorescence-excited Ca2+ Crimson images (excitation: 568 nm). The images shown in Figure 1 represent the GFP-PKCγ fluorescence in the basal condition (Figure 1a) and during maximal translocation (Figure 1b). The time points when the images were taken are marked in the GFP-PKCγ trace. The relative fluorescence intensity represented by both traces was measured in the circular region marked in Figure 1. The maximum change in the relative fluorescence intensity was 1.2 for the GFP-PKCγ trace and 0.2 for the calcium trace. (b) The time course of intracellular Ca2+ concentration changes induced by glutamate (100 μM) in two astrocytes loaded with the Ca2+ fluorescent dye Fluo-3AM and analyzed by confocal microscopy. The oscillatory pattern shown was seen in 6 out of 14 experiments, with single transients and plateaus observed in the other experiments. The maximum change in relative fluorescence intensity was 1.5 ... Glutamate-induced oscillating translocation of DAG binding C1 domains. (a) Glutamate stimulation (1 mM) induced a marked plasma membrane translocation of the tandem DAG binding C1 domains of PKCδ (GFP-C12δ). The left and right panels show images taken before and after maximal translocation occurred. (b) The oscillating time course of the GFP-C12δ fluorescence intensity change in the two astrocytes shown in (a). The calibration bar represents 5 μm. Similar oscillations were observed in 9 out of 21 experiments. The maximum change in relative fluorescence intensity was 0.3. (c) The time course of plasma membrane translocation of a single DAG binding C1 domain from PKCγ (GFP-C1Aγ) measured in parallel with cytosolic Ca2+ oscillations after glutamate stimulation (1 mM). The GFP and the Ca2+ Crimson fluorescent recordings were performed as described in Figure 2a. In 4 out of 8 experiments, the GFP-C1Aγ showed a similar oscillating pattern, with each translocation event being preceded by a Ca2+ spike. The maximum change in relative fluorescence intensity was 0.2 for the GFP-C1Aγ trace and 0.2 for the calcium trace ... Periodic PKC activation as a negative feedback mechanism that supports the generation of astrocyte Ca2+ oscillations and waves. A proposed model of the positive and negative feedback mechanisms that control baseline Ca2+ spiking, Ca2+ oscillations, and waves. The two positive feedbacks that participate in the upstroke of each Ca2+ transient are shown on the left. DAG and IP3 are both expected to oscillate in this model, with each increase in IP3 and DAG being driven by Ca2+ activation of PLC. As shown in the schematic view on the right, periodic desensitization of the GPCR pathway by cPKC is then expected to support the termination of each Ca2+ spike by phosphorylating the GPCR, PLC, and other upstream signaling proteins. The same cPKC-mediated phosphorylation events would then generate a prolonged downregulation with a recovery rate that defines the time period (frequency) when the subsequent Ca2+ spike is triggered ... The effect of the expression of the tandem DAG binding domains of PKCδ (C12δ) on shape and duration of Ca2+ oscillations. Parallel measurements of GFP-C12δ translocation and Ca2+ signals in an astrocyte that exhibited slow baseline Ca2+ spikes. This type of slow Ca2+ transient was not observed in astrocytes in the absence of C1 domain expression. The two superimposed traces in the upper panel show a comparison of the time courses of Ca2+ spikes and repetitive plasma membrane translocation of GFP-C12δ after stimulation with 100 μM glutamate. The magnified view in the lower panel shows that the translocation of the C1 domain is delayed by a few seconds and that the GFP-C12δ translocation is triggered only after reaching a threshold in Ca2+ concentration. The maximum change in relative fluorescence intensity was 1.3 for the GFP-C12δ trace and 0.45 for the calcium trace
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Frequency response and optimal output power. (a) Peak-to-peak voltage and (b) output current of the Hy-TENG versus various vibration frequencies. Straight lines represents the half of maximum value. Both the output voltage and the current show resonance at 5Hz, and the FWHM of the output voltage and current are 22Hz and 250Hz, respectively. (c) Dependence of the output voltage and current at various load resistances. (d) Instantaneous output power density and average power of the Hy-TENG versus various load resistances.
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Simulation of nuclear movement. (A) Schematic diagram illustrating the microtubule-mediated nuclear movement in a fission yeast cell. Vn and ωn are the translational and rotational velocities of the nucleus, respectively. R is the nuclear radius and θi (−πfrequencies used in the simulations are indicated (0.2min−1, 0.4min−1, and 0.6min−1), and error bars represent SD. (E) Probability distributions of the peak amplitudes of the translational displacements of the nucleus from model predictions and experimental measurements. Experimental datasets were obtained from Fig. 2E. The values of the rescue and catastrophe frequencies used in the simulations are indicated, and error bars represent SD.
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Time-dependent bispectral analysis of the Poincaré / non-autonomous Poincaré system with time-dependent coupling. The strength of the coupling used in the numerical simulation is shown in (a). Below are the instantaneous biphase (b) and biamplitude (c) for the autobispectrum of the Poincaré oscillator, corresponding to the frequency pair 0.092–0.53 Hz. The wavelet transforms were calculated using the same parameters as before. ... Wavelet phase coherence between the time series of the Poincaré oscillator and the three complex systems for the seven cases outlined in Section  8.6.3: (a) Gaussian white noise coupling; (b) Gaussian white noise coupling with frequency modulation; (c) Unidirectional coupling; (d) Unidirectional coupling with frequency modulation; (e) Time-dependent unidirectional coupling; (f) Bidirectional coupling; (g) Bidirectional coupling with frequency modulation. Grey lines show the upper 2σ levels from 100 IAAFT surrogates, with shaded areas indicating significant coherence. ... Conditional mutual information in the direction from the Poincaré oscillator to the complex systems: (a) Gaussian white noise coupling; (b) Gaussian white noise coupling with frequency modulation; (c) Unidirectional coupling; (d) Unidirectional coupling with frequency modulation; (e) Time-dependent unidirectional coupling; (f) Bidirectional coupling; (g) Bidirectional coupling with frequency modulation. Dashed lines in this and the following two figures show the upper 2σ levels from IAAFT 100 surrogates and in all cases probability distributions were estimated using 4 bins (16 for joint-probability distributions). ... The shape of the potential for the unforced Duffing oscillator with α=1 and different values of β. ... Comparison between the methods of extracting phase using the Hilbert transform (black) and marked events (red) in the case of unidirectional coupling from the non-autonomous Poincaré oscillator to the autonomous Poincaré oscillator. (Top) Variation in the unwrapped phase after removing the trend using a linear polynomial fit for: (a) The autonomous oscillator; (b) The non-autonomous oscillator. (Bottom) Variation in the return times for: (c) The autonomous oscillator; (d) The non-autonomous oscillator. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
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Plots of the in-phase (χM′) as χM′T (top), and out-of-phase (χM″) (bottom) AC magnetic susceptibilities vs. T in a 3.5G field oscillating at the indicated frequencies for complex 1.
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Airway pressure (Paw) curves during a respiratory cycle under high-frequency percussive ventilation. Upper tracing: inspiration percussive phase (I) and expiration passive phase (E) are indicated. ΔPaw, value of pressure oscillation of the latest percussions before the transition phase between I and E. Lower tracing: expanded tracing contained in the box in the upper tracing, showing the mini-bursts delivered by the ventilator. i, duration of pulse flow administration; e, duration of flow non-administration during a single pulse. Please note the different time scales in the tracings. ... Model, high-frequency ventilation... Techniques, high-frequency ventilator... Mechanics of breathing, high-frequency ventilation
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IR spectra of zeolite LTA external surface using both (a) Morse Potential and (b) Harmonic Oscillator to simulate the OH bond stretch.
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Amplitude of the oscillations (D) of the x (solid line) and y (dotted line) component of the average normalized magnetization for a process γ0H=35mT, J=5.5×108A/cm2, d=30nm, and J0=0.25×108A/cm2 as function of fP. Inset: plot of the temporal evolution of y component of the average magnetization of the same process for fP=750MHz.
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