Beating Effect Research Articles

Microwave Magnetoabsorption Oscillations in Fe-Doped HgSe Crystals

Magnetoresistance oscillations are considered in the case of microwave-radiation absorption in HgSe samples with a different Fe-impurity concentration. From the simultaneous analysis of the field and temperature dependences of the Shubnikov–de Haas oscillations, the effective mass, the Dingle temperature, and the quantum-limit field corresponding to the Fermi level are obtained. A method for analyzing the spectra with several oscillation frequencies, i.e., the beating effect, is proposed. The results are compared with data obtained by Hall measurements.

Beating effects of vector solitons in Bose-Einstein condensates.

We study the beating effects of solitons in multicomponent coupled Bose-Einstein condensate systems. Our analysis indicates that the period of beating behavior is determined by the energy eigenvalue difference in the effective quantum well induced by solitons, and the beating pattern is determined by the eigenstates of a quantum well, which are involved in the beating behavior. We show that the beating solitons correspond to linear superpositions of eigenstates in some quantum wells, and the correspondence relations are identical for solitons in both an attractive interaction and a repulsive interaction condensate. This provides a possible way to understand the beating effects of solitons for attractive and repulsive interaction cases in a unified way, based on the knowledge of quantum eigenstates. Moreover, our results demonstrate many different beating patterns for solitons in multicomponent coupled condensates, in sharp contrast to the beating dark soliton reported before. The beating behavior can be used to test the eigenvalue differences in certain quantum wells, and more abundant beating patterns are expected to exist in more component-coupled systems.

Short-Term Effects of Binaural Beats on EEG Power, Functional Connectivity, Cognition, Gait and Anxiety in Parkinson's Disease.

We applied rhythmic binaural sound to Parkinson's Disease (PD) patients to investigate its influence on several symptoms of this disease and on Electrophysiology (Electrocardiography and Electroencephalography (EEG)). We conducted a double-blind, randomized controlled study in which rhythmic binaural beats and control were administered over two randomized and counterbalanced sessions (within-subjects repeated-measures design). Patients ([Formula: see text], age [Formula: see text], stage I-III Hoehn & Yahr scale) participated in two sessions of sound stimulation for 10[Formula: see text]min separated by a minimum of 7 days. Data were collected immediately before and after both stimulations with the following results: (1) a decrease in theta activity, (2) a general decrease in Functional Connectivity (FC), and (3) an improvement in working memory performance. However, no significant changes were identified in the gait performance, heart rate or anxiety level of the patients. With regard to the control stimulation, we did not identify significant changes in the variables analyzed. The use of binaural-rhythm stimulation for PD, as designed in this study, seems to be an effective, portable, inexpensive and noninvasive method to modulate brain activity. This influence on brain activity did not induce changes in anxiety or gait parameters; however, it resulted in a normalization of EEG power (altered in PD), normalization of brain FC (also altered in PD) and working memory improvement (a normalizing effect). In summary, we consider that sound, particularly binaural-rhythmic sound, may be a co-assistant tool in the treatment of PD, however more research is needed to consider the use of this type of stimulation as an effective therapy.

Color moirés in contact-type three-dimensional displays

Color moires induced at contact-type multiview three-dimensional and light-field imaging are reviewed, slanted color moires are introduced, and the reason why they become invisible as the slanting angle increases is explained. The color moires in the imaging are induced by the structural uniqueness of the imaging, i.e., viewing zone-forming optics (VZFO) on the display panel. The moires behave differently from those by the beating effect. They are (1) basically chirped, (2) their fringe numbers and phases are also varying according to the changes in viewer’s viewing positions and viewing angles at a given viewing distance, (3) the pattern period of the VZFO is at least more than several times that of the pixel pattern, and (4) they are colored. The color moires can hardly be eliminated because they are induced structurally, but they can be minimized by either reducing the regularity of the pixel pattern using a diffuser between the panel and the VZFO or aligning VZFO’s pattern to have a certain slanting angle with the pixel pattern in the panel.

Cumulative effects of theta binaural beats on brain power and functional connectivity

Audiovisual stimuli with specific frequency can cause the brain to oscillate in the same frequency, something which is also called brain entrainment. One method to entrain the brain through the auditory system is binaural beats. Binaural beats are two rhythmic tones with slightly different frequency which are presented separately to each ear. The brain perceives an illusionary signal with the frequency of the difference of the two exerted tones and oscillates in that frequency. There are contradictory findings in the previous studies in which some researchers could not entirely observe this phenomenon. In this paper we propose a protocol to inspect whether binaural beats can change the power and connectivity of the brain and also how lengthening the stimuli, interchangeably with pink noise, will affect the outcomes. Fifteen healthy participants attended this study and their EEG signals were recorded during presentation of 200 Hz and 207 Hz sinusoidal tones to their left and right ears respectively. Total 9 min of binaural beats were divided into three 3-min blocks which were separated by 1 min of pink noise to prevent the brain from habituating to the stimuli. Our results showed that 3 min of 7 Hz binaural beats is not enough to entrain the brain, but applying 6 min of stimulation could change the relative power in the temporal and parietal lobes and further exposure to 9 min of stimuli could also alter the brain network, evaluated by the graph theory.

The Radial Velocity Variability of the K-giant γ Draconis: Stellar Variability Masquerading as a Planet

Abstract We present precise stellar radial velocity (RV) measurements of γ Dra taken from 2003 to 2017. The data from 2003 to 2011 show coherent, long-lived variations with a period of 702 days. These variations are consistent with the presence of a planetary companion having m sin i = 10.7 M Jup whose orbital properties are typical for giant planets found around evolved stars. An analysis of the Hipparcos photometry, Ca ii S-index measurements, and measurements of the spectral line shapes during this time show no variations with the RV of the planet, which seems to “confirm” the presence of the planet. However, RV measurements taken from 2011–2017 seem to refute this. From 2011–2013, the RV variations virtually disappear, only to return in 2014 but with a noticeable phase shift. The total RV variations are consistent either with amplitude variations on timescales of ≈10.6 year, or the beating effect between two periods of 666 and 801 days. It seems unlikely that both these signals stem from a two-planet system. A simple dynamical analysis indicates that there is only a 1%–2% chance that the two-planet system is stable. Rather, we suggest that this multi-periodic behavior may represent a new form of stellar variability, possibly related to oscillatory convective modes. If such intrinsic stellar variability is common around K giant stars and is attributed to planetary companions, then the planet occurrence rate among these stars may be significantly lower than thought.

Gamma Binaural Beats and its Quality Assessment

Due to brain's internal wiring, a beating effect will be created in it as soon as two sine waves with slightly different frequencies be applied to each ear. Brain's response to such beat remains controversial; therefore and in addition to author's desire toward investigate the role of beat and carrier frequencies upon the brain, this research introduces a new way for quantifying such phenomenon by using an objective methods of quality assessment. In such method, the criteria of error visibility (differences) between tones had been tested. Gamma wave had been used here to investigate its beat and carrier frequencies effects inside the brain. The reversal relationship between (carrier-beat) frequencies activates uponStructural Similarity Index Metric (SSIM) andStructural Dissimilarity Metric (DSSIM) values. After all and in order to detect the best series in Gamma brain waves to investigate and quantize, carrier frequency produces a meaningful variation than beat frequency one.

Осцилляции микроволнового магнитопоглощения в кристаллах HgSe с примесью Fe

AbstractMagnetoresistance oscillations are considered in the case of microwave-radiation absorption in HgSe samples with a different Fe-impurity concentration. From the simultaneous analysis of the field and temperature dependences of the Shubnikov–de Haas oscillations, the effective mass, the Dingle temperature, and the quantum-limit field corresponding to the Fermi level are obtained. A method for analyzing the spectra with several oscillation frequencies, i.e., the beating effect, is proposed. The results are compared with data obtained by Hall measurements.

Effect of alpha and gamma binaural beats on reaction time and short-term memory

Background: Binaural beats, a kind of cortical entrainment, are an auditory illusion that occurs when two sinusoidal waves at slightly different frequencies are presented separately to each ear. Binaural beats influence behavior and cognition through the process of cognitive or neural entrainment. Different types of binaural beats, based on their electroencephalogram frequencies, have shown to have varied effects on various domains of cognition. Aims and Objectives: The aims of this study were to compare the effects of alpha and gamma binaural beats on auditory reaction time (ART), visual reaction time (VRT), and short-term memory. Materials and Methods: The study was conducted on 40 individuals (20 males and 20 females) with age ranging between 22 and 30 years. The study was conducted in 3 different sessions. In each session, ART, VRT, and short-term memory were assessed. In the first session, the individuals were assessed without any intervention. In one session, they were presented with alpha binaural beats (10 Hz), and in another session, they were presented with gamma binaural beats (40 Hz). Results: The results of our study showed a statistically significant decrease in ART and VRT after entrainment with alpha and gamma binaural beats. Memory scores although improved were not statistically significant. Conclusions: This study provides evidence that entrainment by binaural beats in the alpha and gamma frequency range can enhance attention. The binaural entrainment may have useful applications in conditions where there exist attention deficits and in tasks that require continuous attention.

Effects of Healing Beat on autonomic balance, heart rate and anxiety: A randomized controlled trial

본 연구는 스트레스원에 노출된 불안 상황에서 대상자의 사전 안정시 심박동수와 동일한 Healing Beat를 적용하였을 때 신체의 불안 회복력에 미치는 효과를 확인하기 위한 무작위 대조군 전후 실험연구이며. 이를 위해 자율신경균형, 심박동수 및 불안을 측정하였다. 대상자 선정은 D시 소재 대학교에서 모집공고를 통해 ...

Effective viscosity of a suspension of flagellar-beating microswimmers: Three-dimensional modeling.

Micro-organisms usually can swim in their liquid environment by flagellar or ciliary beating. In this numerical work, we analyze the influence of flagellar beating on the orbits of a swimming cell in a shear flow. We also calculate the effect of the flagellar beating on the rheology of a dilute suspension of microswimmers. A three-dimensional model is proposed for Chlamydomonas Reinhardtii swimming with a breaststroke-like beating of two anterior flagella modeled by two counter-rotating fore beads. The active swimmer model reveals unusual angular orbits in a linear shear flow. Namely, the swimmer sustains orientations transiently across the flow. Such behavior is a result of the interplay between shear flow and the swimmer's periodic beating motion of flagella, which exert internal torques on the cell body. This peculiar behavior has some significant consequences on the rheological properties of the suspension. We calculate Einstein's viscosity of the suspension composed of such isolated modeled microswimmers (dilute case) in a shear flow. We use numerical simulations based on a Rotne-Prager-like approximation for hydrodynamic interaction between simplified flagella and the cell body. The results show an increased intrinsic viscosity for active swimmer suspensions in comparison to nonactive ones as well as a shear thinning behavior in accordance with previous experimental measurements [Phys. Rev. Lett. 104, 098102 (2010)10.1103/PhysRevLett.104.098102].

Binaural Beat: A Failure to Enhance EEG Power and Emotional Arousal.

When two pure tones of slightly different frequencies are delivered simultaneously to the two ears, is generated a beat whose frequency corresponds to the frequency difference between them. That beat is known as acoustic beat. If these two tones are presented one to each ear, they still produce the sensation of the same beat, although no physical combination of the tones occurs outside the auditory system. This phenomenon is called binaural beat. In the present study, we explored the potential contribution of binaural beats to the enhancement of specific electroencephalographic (EEG) bands, as previous studies suggest the potential usefulness of binaural beats as a brainwave entrainment tool. Additionally, we analyzed the effects of binaural-beat stimulation on two psychophysiological measures related to emotional arousal: heart rate and skin conductance. Beats of five different frequencies (4.53 Hz -theta-, 8.97 Hz -alpha-, 17.93 Hz -beta-, 34.49 Hz -gamma- or 57.3 Hz -upper-gamma) were presented binaurally and acoustically for epochs of 3 min (Beat epochs), preceded and followed by pink noise epochs of 90 s (Baseline and Post epochs, respectively). In each of these epochs, we analyzed the EEG spectral power, as well as calculated the heart rate and skin conductance response (SCR). For all the beat frequencies used for stimulation, no significant changes between Baseline and Beat epochs were observed within the corresponding EEG bands, neither with binaural or with acoustic beats. Additional analysis of spectral EEG topographies yielded negative results for the effect of binaural beats in the scalp distribution of EEG spectral power. In the psychophysiological measures, no changes in heart rate and skin conductance were observed for any of the beat frequencies presented. Our results do not support binaural-beat stimulation as a potential tool for the enhancement of EEG oscillatory activity, nor to induce changes in emotional arousal.

Before and after Retrofit Behavior and Performance of a 55-Story Tall Building Inferred from Distant Earthquake and Ambient Vibration Data

A sparsely instrumented 55-story building in Osaka, Japan, had recorded unprecedented, severe, and long-duration, long-period resonating responses during the 11 March 2011 M9.0 Tohoku earthquake that occurred at 767 km distance. Thereafter, studies of the records resulted in the implementation of a significant retrofit design, comprising dampers and buckling restrained braces (BRBs). The responses of the retrofitted building were also recorded during the 24 April 2016 M7.3 Kumamoto earthquake that occurred at 478 km. The earthquake and on-demand acquired ambient response data are analyzed in this study to assess the impact of this rare, retrofitted and instrumented tall building subjected to long period strong shaking from events originating at far distances. As expected, the fundamental frequency and critical damping ratio of the building increased, albeit small, after the retrofit as compared to before the retrofit. Increase of damping percentage is a positive finding and indicates that even larger percentages may be attained under shaking stronger than the 2016 event. The records indicate that the building still experiences significant resonance, torsion, as well as a beating effect.

Effect of magnetic field on the character of fluorescence of dense and cold atomic ensembles excited by pulsed radiation

Specific features of fluorescence of dense and cold nondegenerate atomic ensembles in an external constant magnetic field are analyzed theoretically. The angular distribution, polarization properties, as well as the spectral composition of fluorescence radiation are calculated. The time variation of these characteristics after the end of the excitation pulse is analyzed. The dependence of the properties of secondary radiation on the duration and carrier frequency of the pulse is investigated. It is shown that, for dense clouds in which the free path length of quasiresonance photons is commensurate with the interatomic distance, the magnetic field significantly modifies all the observable properties of the radiation. Under these conditions, the trapping time may increase by tens of times. Magnetic field enhances the effect of quantum beats observed on time scales commensurate with the lifetime of the excited states of atoms. For individual polarization channels, this field also intensifies the phenomenon of coherent backscattering (CBS). The phenomena found are explained by the effect of magnetic field on the character of resonance dipole–dipole interaction and, as a result, on the specific features of collective phenomena in dense atomic ensembles.

R-Wave Peak Time at Lead II in Adults With Ventricular Premature Beats, Bundle Branch Block and Left Anterior Fascicular Block

BackgroundRecently, the R-wave peak time (RWPT) at lead II was reported to be a helpful and simple tool for differentiating wide QRS complex tachycardias with a RWPT ≥ 50ms for ventricular tachycardia diagnosis. Our previous study showed that the duration of RWPT at lead II in adults was ≈29ms. However, the effects of ventricular premature beats (VPBs), bundle branch block (BBB) or left anterior fascicular block (LAFB) on RWPT at lead II remain unknown. MethodsThe study was conducted in the First Affiliated Hospital of Shantou University Medical College in Southern China. Adults with VPBs, BBB or LAFB were included. RWPT at lead II was determined. ResultsCompared with the control groups, the right BBB, LAFB, RWPT were longer in groups with left BBB and VPBs. Compared with the group with left BBB, the group with VPBs had a significantly longer RWPT at lead II (54.20 ± 18.52 versus 84.76 ± 16.38ms, P < 0.01). ConclusionOur study showed that there is a significant difference in the RWPT at lead II between groups with left BBB, ventricular premature beat, right BBB and LAFB. A RWPT of 50ms may be optimal to differentiate between ventricular tachycardia and supraventricular tachycardia with right left BBB and LAFB, but not with left BBB.

Analysis of the quasiperiodic response of a generalized van der Pol nonlinear system in the resonance zone

The paper addresses the description of the complex behavior of simple nonlinear systems that are excited in the neighborhood of the resonance frequency. Depending on the detuning of the excitation frequency, resonant response can vary from purely stationary to various cases of quasiperiodic or chaotic response. This type of response is characterized by regular or irregular changes of the amplitude, which, in the quasiperiodic case, represents the beating effect. The beating frequency then changes from zero in resonance to a positive value outside the resonance zone. The ratio of the energy content of quasiperiodic and stationary components decreases in the same time. Starting at a certain detuning, the quasiperiodic component fully vanishes and the stationary component absorbs the whole response energy.The motivation of this study originates from the aeroelasticity of large bridges, the tuned mass damper application, and other domains of civil engineering, where beating effects have been observed in the past. Such effects are very dangerous; hence, robust theoretical background for the design of adequate countermeasures should be developed. Nevertheless, investigations of the internal structure of a quasiperiod and its dependence on the difference between excitation frequency and eigenfrequency were conducted on a heuristic basis and an objective theoretical background is still missing.A qualitative analysis of nonlinear systems using combinations of harmonic balance, small-parameter methods, and perturbation techniques is presented in the paper. Parametric evaluations are presented along with a discussion concerning the applicability of the presented approach.

The effects of music therapy on transition outcomes in adolescents and young adults with sickle cell disease.

Background The Build, Educate, Advance, Transition, in Sickle cell disease (BEATS) music therapy program was developed to address health challenges faced by adolescents/young adults (AYA) with sickle cell disease (SCD) during the transition to adult medical care. Objective The purpose of this study was to investigate the effects of BEATS on self-efficacy, trust, knowledge about SCD, and adherence in adolescents/young adults (AYA) with SCD. Subjects Thirty AYA with SCD, 18-23 years old, recruited from an adult SCD clinic agreed to participate in four BEATS sessions over 1 year. Methods Self-efficacy, trust and SCD knowledge were measured prospectively at baseline and months 3, 6, 9, and 12. Adherence to clinic appointments and healthcare utilization were measured retrospectively from medical records. A repeated measures linear mixed-effect model with compound symmetry covariance structure was used to fit the data. Results BEATS participants demonstrated a significant improvement in SCD knowledge (p = 0.0002) compared to baseline, an increase in acute care clinic, but not emergency department, utilization (p = 0.0056), and a non-significant improvement in clinic attendance (p = 0.1933). Participants' subjective evaluations revealed a positive response to BEATS. There were no significant changes in self-efficacy, trust, hospital admissions, or blood transfusion adherence. Conclusion Culturally tailored, developmentally appropriate music therapy transition interventions can concretely improve SCD knowledge and may improve transition for AYA with SCD.

Control of a Pediatric Pulsatile Ventricular Assist Device: A Hybrid Cardiovascular Model Study.

The aim of this work is to study pediatric pneumatic ventricle (PVAD) performance, versus VAD rate (VADR) and native heart rate (HR) ratio Rr (VADR/HR). The study uses a hybrid model of the cardiovascular system (HCS). HCS consists of a computational part (a lumped parameter model including left and right ventricles, systemic and pulmonary arterial and venous circulation) interfaced to a physical part. This permits the connection of a VAD (15 mL PVAD). Echocardiographic and hemodynamic data of a pediatric patient (average weight 14.3 kg, HR 100 bpm, systemic pressure 75/44 mm Hg, CO 1.5 L/min) assisted apically with asynchronous PVAD were used to set up a basal condition in the model. After model tuning, the assistance was started, setting VAD parameters (ejection and filling pressures, systole duration) to completely fill and empty the PVAD. The study was conducted with constant HR and variable VADR (50-120, step 10, bpm). Experiments were repeated for two additional patients' HRs, 90 and 110 bpm and for two values of systemic arterial resistance (Ras ) and Emax . Experimental data were collected and stored on disk. Analyzed data include average left and right ventricular volumes (LVV, RVV), left ventricular flow (LVF), VAD flow (VADF), and total cardiac output (COt). Data were analyzed versus Rr. LVV and RVV are sensitive to Rr and a left ventricular unloading corresponds in general to a right ventricular loading. In the case of asynchronous assistance, frequency beats are always present and the beat rate is equal to the difference between HR and VADR. In the case of pulsatile asynchronous LVAD assistance, VADR should be chosen to minimize frequency beat effects and right ventricular loading and to maximize left ventricular unloading.

Deconvoluting Kinase Inhibitor Induced Cardiotoxicity.

Many drugs designed to inhibit kinases have their clinical utility limited by cardiotoxicity-related label warnings or prescribing restrictions. While this liability is widely recognized, designing safer kinase inhibitors (KI) requires knowledge of the causative kinase(s). Efforts to unravel the kinases have encountered pharmacology with nearly prohibitive complexity. At therapeutically relevant concentrations, KIs show promiscuity distributed across the kinome. Here, to overcome this complexity, 65 KIs with known kinome-scale polypharmacology profiles were assessed for effects on cardiomyocyte (CM) beating. Changes in human iPSC-CM beat rate and amplitude were measured using label-free cellular impedance. Correlations between beat effects and kinase inhibition profiles were mined by computation analysis (Matthews Correlation Coefficient) to identify associated kinases. Thirty kinases met criteria of having (1) pharmacological inhibition correlated with CM beat changes, (2) expression in both human-induced pluripotent stem cell-derived cardiomyocytes and adult heart tissue, and (3) effects on CM beating following single gene knockdown. A subset of these 30 kinases were selected for mechanistic follow up. Examples of kinases regulating processes spanning the excitation–contraction cascade were identified, including calcium flux (RPS6KA3, IKBKE) and action potential duration (MAP4K2). Finally, a simple model was created to predict functional cardiotoxicity whereby inactivity at three sentinel kinases (RPS6KB1, FAK, STK35) showed exceptional accuracy in vitro and translated to clinical KI safety data. For drug discovery, identifying causative kinases and introducing a predictive model should transform the ability to design safer KI medicines. For cardiovascular biology, discovering kinases previously unrecognized as influencing cardiovascular biology should stimulate investigation of underappreciated signaling pathways.

The Impact of Monaural Beat Stimulation on Anxiety and Cognition.

Application of auditory beat stimulation has been speculated to provide a promising new tool with which to alleviate symptoms of anxiety and to enhance cognition. In spite of reportedly similar EEG effects of binaural and monaural beats, data on behavioral effects of monaural beats are still lacking. Therefore, we examined the impact of monaural beat stimulation on anxiety, mood and memory performance. We aimed to target states related to anxiety levels and general well-being, in addition to long-term and working memory processes, using monaural beats within the range of main cortical rhythms. Theta (6 Hz), alpha (10 Hz) and gamma (40 Hz) beat frequencies, as well as a control stimulus were applied to healthy participants for 5 min. After each stimulation period, participants were asked to evaluate their current mood state and to perform cognitive tasks examining long-term and working memory processes, in addition to a vigilance task. Monaural beat stimulation was found to reduce state anxiety. When evaluating responses for the individual beat frequencies, positive effects on state anxiety were observed for all monaural beat conditions compared to control stimulation. Our results indicate a role for monaural beat stimulation in modulating state anxiety and are in line with previous studies reporting anxiety-reducing effects of auditory beat stimulation.