The Integrated Optokinetic Nystagmus Inter-saccadic Interval Scales Statistical Different In a Group of Vertigo Patients Depended On The Stimulation Velocity, But Not For Healthy Subjects

Optokinetic nystagmus is rhythmic eye movements, back and forth, with a slow and fast phase, when the eyes are presented for full-field visual stimulus. OKN was recorded in 20 healthy subjects and 20 patients suffering from vertigo, for four conditions: stripes moving 30 o/s left and right and 60 o/s left and right. Calculating the scaling, the spread over time, for the integrated optokinetic nystagmus inter-saccadic interval, the time intervals between the onsets of consecutive fast components, shows lower Hurst exponent for velocity stimulation of 30o/s compared to 60o/s for both patients and health subjects, but only reach statistical differences for the group of patients.

Quantum Key Distribution Transmitter Chip Based on Hybrid-integration of Silica and Lithium Niobates

A quantum key distribution transmitter chip based on hybrid‐integration of silica planar light‐wave circuit (PLC) and lithium niobates (LN) modulator PLC is presented. The silica part consists of a tunable directional coupler and 400 ps delay line, and the LN part is made up of a Y‐branch, with electro‐optic modulators on both arms. The two parts are facet‐coupled to form an asymmetric Mach‐Zehnder interferometer. We have successfully encoded and decoded four BB84 states at 156.25 MHz repetition rate. Fast phase‐encoding of 0 or π has been achieved, with interference fringe visibilities 78.53% and 82.68% for state |+> and |‐>, respectively. With the aid of an extra off‐chip LN intensity modulator, two time‐bin states have been prepared and the extinction ratios are 18.65 dB and 15.46 dB for state |0> and |1>, respectively.

An Efficient BPSK Modulation and Demodulation Scheme with the Complete Removal of Fading

A novel non-coherent <i>BPSK</i> modulation and demodulation scheme is proposed to remove both slow and fast fading completely. We formulate a compound function that reflects the different characteristics of both slow and fast fading and prove that the scheme can remove fading from the function completely. The scheme is reified by a simple architecture that can remove slow and fast phase shifts completely from the received signals. It is shown by using analytical model and numerical data that the proposed scheme outperforms other ones significantly under the presence of both slow and fast fading. The analytical results also show that the proposed scheme can work well even with a small sampling rate, resulting in a wireless device with low energy consumption.

An Efficient BPSK Modulation and Demodulation Scheme with the Complete Removal of Fading

A novel non-coherent <i>BPSK</i> modulation and demodulation scheme is proposed to remove both slow and fast fading completely. We formulate a compound function that reflects the different characteristics of both slow and fast fading and prove that the scheme can remove fading from the function completely. The scheme is reified by a simple architecture that can remove slow and fast phase shifts completely from the received signals. It is shown by using analytical model and numerical data that the proposed scheme outperforms other ones significantly under the presence of both slow and fast fading. The analytical results also show that the proposed scheme can work well even with a small sampling rate, resulting in a wireless device with low energy consumption.

Analysis of the Strong and Weak Monotonic External Stability of the Resonance in a Perturbed Dynamical System

A perturbed dynamical system involving two ordinary differential equations is under review. Whereupon, the differential equation for determining the fast phase contains the ratio of the two frequencies. When these frequencies coincide for a long time, a resonance is implemented in this system. The aim of this paper is to obtain the conditions of monotonic external stability and instability of this resonance. The sufficient conditions for the external stability and instability of the resonance defined in this paper assume that the signs of the analyzed derivatives remain unchanged in the non-resonant section of the change in the independent variable. This paper gives a new classification of the phenomenon of external stability of resonance, which includes weak, linear, and strong stability. It should be noted that the conditions of monotonic external stability and instability of the resonance presented in this paper can be used in various scientific and technological problems, in which resonances are observed. Particularly, the concluding part of the paper considers the application of the results obtained within the framework of the problem of the perturbed motion of a rigid body relative to a fixed point.

Velocity and azimuthal anisotropy structure underneath the Reelfoot Rift region from Rayleigh wave phase velocity dispersion curves

SUMMARY Phase velocity and azimuthal anisotropy maps for fundamental mode Rayleigh waves are determined for a portion of the central United States including the seismically active Reelfoot Rift (RFR) and the enigmatic Illinois Basin. Dense seismic array installations of the Northern Embayment Lithosphere Experiment, the EarthScope transportable array and the Ozarks Illinois Indiana Kentucky array allow a detailed investigation of phase velocity and anisotropy in a broad period range (20–100s).We obtain more than 12 000 well-constrained, unique two-station paths from teleseismic events. The two-station method is used to determine dispersion curves and these are inverted for isotropic phase velocity maps and azimuthal anisotropy maps for each period. The presence of fast phase velocities at lower crustal and uppermost mantle depths is found below the RFR, and Ste. Genevieve and Wabash Valley fault zones. At periods of 30s and higher, the RFR is underlain by slow phase velocities and is flanked to the NW and SE by regions of fast velocity. Fast phase velocities are present below the centre of the Illinois Basin in the period range 75–100s. Anisotropy fast axis orientations display complex patterns for each period and do not trend parallel to the direction of absolute plate motion. Anisotropy fast directions are consistently parallel to the trend of the RFR from 50s to higher periods, suggesting the presence of either frozen-in anisotropic fabric or fabric related to material transport from a recently discovered, pronounced low velocity zone below the Mississippi Embayment.

The development of L-type Ca2+ current mediated alternans does not depend on the restitution slope in canine ventricular myocardium

Cardiac alternans have crucial importance in the onset of ventricular fibrillation. The early explanation for alternans development was the voltage-driven mechanism, where the action potential (AP) restitution steepness was considered as crucial determining factor. Recent results suggest that restitution slope is an inadequate predictor for alternans development, but several studies still claim the role of membrane potential as underlying mechanism of alternans. These controversial data indicate that the relationship of restitution and alternans development is not completely understood. APs were measured by conventional microelectrode technique from canine right ventricular papillary muscles. Ionic currents combined with fluorescent measurements were recorded by patch-clamp technique. APs combined with fluorescent measurements were monitored by sharp microelectrodes. Rapid pacing evoked restitution-independent AP duration (APD) alternans. When non-alternating AP voltage command was used, Ca2+i-transient (CaT) alternans were not observed. When alternating rectangular voltage pulses were applied, CaT alternans were proportional to ICaL amplitude alternans. Selective ICaL inhibition did not influence the fast phase of APD restitution. In this study we found that ICaL has minor contribution in shaping the fast phase of restitution curve suggesting that ICaL—if it plays important role in the alternans mechanism—could be an additional factor that attenuates the reliability of APD restitution slope to predict alternans.