Hz Intervals Research Articles

Development of Ozone Generator Mini with DDBD (Double Dielectric Barrier Discharge) Technology at Atmospheric Air Pressure

<p class="Abstract">Pesticide residues in fruits and vegetables pose a danger to human health if consumed for a certain period. This requires appropriate technology for household scale and is environmentally friendly. Ozone is a strong oxidizing agent capable of degrading pesticide residues in fruits and vegetables. Ozone is a green chemical compound because it does not produce harmful derivative compounds, and is even friendly to the environment. The development of a mini ozone generator with DBD technology has been successfully carried out. The DDBD reactor is made of Pyrex glass with a length of 10 cm and an outer diameter of 4 cm. The reactor uses electrodes made of copper plates. The outer electrode is 13 cm long and 5 cm wide, while the inner electrode is 10 cm long and 5 cm wide. Optimization of the mini ozone generator is carried out using high voltage AC pulses whose pulse frequency can be varied from 30 to 60 Hz with 10 Hz intervals. The free air flow rate was varied at 0.2 – 0.8 lpm with an interval of 0.2 lpm. The optimum ozone production of 480 mg/l was obtained at a voltage setting of 2.8 kV and a frequency of 50 Hz and a flow rate of 0.2 lpm. In this setting, the DDBD reactor consumes 9.32 watts of power. The development of mini ozone generator technology has the potential to be applied on a household scale because of the small reactor size and low power consumption. </p>

Excellent energy density and power density achieved in NaNbO3-based relaxor ferroelectric ceramics

(1-x)NaNbO3-xBi(Ni0.5Hf0.5)O3 [(1-x)NN-xBNH, x = 0.10, 0.15, 0.20 and 0.25] lead-free ferroelectric ceramics were fabricated via a standard solid-phase reaction method, in order to obtain superior energy storage properties. BNH is introduced into the NN lattice to limit grain growth and improve the breakdown field strength as a second component. As the results indicate, a high Wrec of 6.45 J/cm3 and a breakdown field strength (Eb) of 380 kV/cm were achieved for the 0.80NN-0.20BNH ceramic, which was dependent on the nonequivalent replacement at the B site. In addition, the ceramics maintain significant stability over a frequency range of 10 Hz to 1000 Hz and temperature intervals from 30 up to 120 °C. Exceptional charge/discharge properties of high power density (PD = 215 MW/cm3) and current density (CD = 1346 A/cm2) along with an ultra-fast discharge rate (54 ns) were acquired. These results demonstrate that the 0.80NN-0.20BNH ceramic is an energy storage material with high potential.

The Performance of a Lip-Sync Imagery Model, New Combinations of Signals, a Supplemental Bond Graph Classifier, and Deep Formula Detection as an Extraction and Root Classifier for Electroencephalograms and Brain–Computer Interfaces

Many current brain–computer interface (BCI) applications depend on the quick processing of brain signals. Most researchers strive to create new methods for future implementation and enhance existing models to discover an optimal feature set that can operate independently. This study focuses on four key concepts that will be used to complete future works. The first concept is related to potential future communication models, whereas the others aim to enhance previous models or methodologies. The four concepts are as follows. First, we suggest a new communication imagery model as a substitute for a speech imager that relies on a mental task approach. As speech imagery is intricate, one cannot imagine the sounds of every character in every language. Our study proposes a new mental task model for lip-sync imagery that can be employed in all languages. Any character in any language can be used with this mental task model. In this study, we utilized two lip-sync movements to indicate two sounds, characters, or letters. Second, we considered innovative hybrid signals. Choosing an unsuitable frequency range can lead to ineffective feature extractions. Therefore, the selection of an appropriate frequency range is crucial for processing. The ultimate goal of this method is to accurately discover distinct frequencies of brain imagery activities. The restricted frequency range combination presents an initial proposal for generating fragmented, continuous frequencies. The first model assesses two 4 Hz intervals as filter banks. The primary objective is to discover new combinations of signals at 8 Hz by selecting filter banks with a 4 Hz scale from the frequency range of 4 Hz to 40 Hz. This approach facilitates the acquisition of efficient and clearly defined features by reducing similar patterns and enhancing distinctive patterns of brain activity. Third, we introduce a new linear bond graph classifier as a supplement to a linear support vector machine (SVM) when handling noisy data. The performance of the linear support vector machine (SVM) significantly declines under high-noise conditions. To complement the linear support vector machine (SVM) in noisy-data situations, we introduce a new linear bond graph classifier. Fourth, this paper presents a deep-learning model for formula recognition that converts the first-layer data into a formula extraction model. The primary goal is to decrease the noise in the formula coefficients of the subsequent layers. The output of the final layer comprises coefficients chosen by different functions at various levels. The classifier then extracts the root interval for each formula, and a diagnosis is established based on these intervals. The final goal of the last idea is to explain the main brain imagery activity formula using a combination formula for similar and distinctive brain imagery activities. The results of implementing all of the proposed methods are reported. The results range between 55% and 98%. The lowest result is 55% for the deep detection formula, and the highest result is 98% for new combinations of signals.

Use of Interference Patterns to Control Sound Field Focusing in Shallow Water

The possibility of controlling localized fields in multimode shallow water waveguides based on the principle of interference invariance was studied. Within the framework of the numerical experiments in a wide frequency range of 100–350 Hz and range intervals of 10–100 km, the possibilities of focusing the sound field by wavefront reversal and controlling of the focusing of the focal spot by frequency tuning in shallow water waveguides was analyzed. The focal spot scanning was carried out by frequency tuning with a fixed distribution of the sound field at receiving and transmitting vertical antenna apertures. A comparative analysis of the features of focusing and focal spot control for summer and winter stratification of the water layer was carried out. It is shown that the parameters of the focal spot during frequency tuning were more stable in the winter waveguide. It is demonstrated that the sound frequency tuning had a piecewise continuous character and was carried out on a domain of one continuous track and jump-passing on the other track in accordance with the waveguide interference fringes in the range–frequency domain.

DIAGNOSTIC IMPORTANCE OF THE CARHART NOTCH IN PATIENTS WITH CHRONIC OTITIS MEDIA

Objective
 The false sensorineural loss caused by otosclerosis
 due to stapes fixation is known as the Carhart notch.
 To examine the changes in air-bone gap (ABG)
 and bone-conduction (BC) hearing thresholds by
 comparing the preoperative and postoperative
 audiometry results in patients with chronic otitis media
 (COM), to investigate the effects of air conduction
 (AC) on BC, to determine the effects of postoperative
 improvement in AC on BC, to detect the presence
 of the Carhart notch in COM, and to determine the
 effects of surgery on the Carhart notch.
 Material and Methods
 A total of 104 patients who underwent type 1
 tympnoplasty between January 2012 - March 2017
 in our clinic were included in this retrospective study.
 Parameters measured during the preoperative and
 postoperative sixth month audiometric evaluation
 comprised AC hearing thresholds at the frequencies
 of 250-8,000 Hz, BC hearing thresholds at 500-4,000
 Hz, and ABG values at 500-4,000 Hz intervals.
 Results
 Before surgery, the Carhart notch was present in
 46 (44.2%) of the 104 patients. Postoperatively, the
 Carhart notch was observed to have been corrected
 in 25 (54.3%) of these patients (p=0.029).
 Conclusion
 After tympanoplasty, significant improvement in ABG
 may lead to improvement in BC at 2,000 Hz in COM
 cases with an intact and mobile ossicular chain. The
 Carhart notch may also be present in COM.

Facilitation of Motor Evoked Potentials in Response to a Modified 30 Hz Intermittent Theta-Burst Stimulation Protocol in Healthy Adults.

Theta-burst stimulation (TBS) is a form of repetitive transcranial magnetic stimulation (rTMS) developed to induce neuroplasticity. TBS usually consists of 50 Hz bursts at 5 Hz intervals. It can facilitate motor evoked potentials (MEPs) when applied intermittently, although this effect can vary between individuals. Here, we sought to determine whether a modified version of intermittent TBS (iTBS) consisting of 30 Hz bursts repeated at 6 Hz intervals would lead to lasting MEP facilitation. We also investigated whether recruitment of early and late indirect waves (I-waves) would predict individual responses to 30 Hz iTBS. Participants (n = 19) underwent single-pulse TMS to assess MEP amplitude at baseline and variations in MEP latency in response to anterior-posterior, posterior-anterior, and latero-medial stimulation. Then, 30 Hz iTBS was administered, and MEP amplitude was reassessed at 5-, 20- and 45-min. Post iTBS, most participants (13/19) exhibited MEP facilitation, with significant effects detected at 20- and 45-min. Contrary to previous evidence, recruitment of early I-waves predicted facilitation to 30 Hz iTBS. These observations suggest that 30 Hz/6 Hz iTBS is effective in inducing lasting facilitation in corticospinal excitability and may offer an alternative to the standard 50 Hz/5 Hz protocol.

Analyzing vibration parameters of a modern high-speed engine during operation

The paper presents results of experimental research into vibration parameters of a modern electronic control-enabled main high-speed engine, Caterpillar CAT 3516B as obtained during a running trial of a sea tug. CAT 3500 series Caterpillar high-speed engines are extensively used in sea tugs; there are about 40 units installed in vessels operating in the Azov and Black Sea region. The research technique involved measurement of vibration displacement, vibration velocity, vibration acceleration at an engine and its turbocharger components. The conducted experimental research has shown that in order to evaluate the technical state of an engine, it is necessary to measure vibration displacement and vibration velocity in a frequency range from 1 to 1000 Hz at 0.1 Hz intervals. For turbochargers, the vibration acceleration shall be measured in a frequency range from 1 to 15000 Hz at 1 Hz intervals. The results of the experimental research allowed determining necessary conditions for measurement of vibration parameters of Caterpillar CAT-3500 series modern high-speed engines commonly used in sea tugs. The experimental research into vessel installations by in-place diagnostics at operating sea-going vessels forms a foundation of an autonomous ship control system.

The Characteristic of Variable Frequency Drive for Water Flow Control in the SFC Plant

One of several techniques to control fluid flow-rate through a pump is using variable frequency drive. This paper presents how experiment be able to perceive the characteristic of variable frequency drive (VFD) to control water flow-rate in the Simulator Flow Control (SFC) plant. The SFC plant is developed for a fluid course learning simulator. The user would be able to set the desired value of frequency or flow-rate through a convenient interface. To provide it, the characteristic of VFD-frequency-to-flow-rate must be firstly observed, as reported in this paper. The fluid flow-rate control is designed without an electric valve, but using VFD to drive the 250 Watt water pump. In this first development, the SFC Plant successfully work with various water flow-rate from 2 Liter per minute until 20 Liter per minute by changing the frequency input of VFD. The water flow-rate was measured by manual rotameter, the flow sensor has not been applied yet in this first development. In this experiment, the VFD’s frequency was set from 10 Hz to 36 Hz with 2 Hz intervals. Result showed that VFD frequency is proportional to water flow-rate. The higher frequency given to VFD, the faster rotational motor of water pump generated and then given rise to water flow-rate. Using linear graphic approach, the characteristic is shown through the linearity coefficient of 0,68 and constant value of 3.43. This characteristic value would be useful for open-loop-control and user interface programming in next step of development.

Cluster Analysis of Lithology Grouping Trends using Principal Component Spectral Analysis and Complex Seismic Attributes

Cluster analysis is used to determine possible lithology groupings on the basis of information from seismic data. Specifically, k-means is used in the cluster analysis of different lithologies. The data center is determined randomly and updated through an iterative process (unsupervised). The cluster analysis process involves combinations of complex seismic attributes and spectral decomposition as inputs. The complex seismic attributes are reflection strength and cosine phase. Reflection strength clearly describes the lithology boundary while the cosine phase describes the lithologies. Spectral decomposition is used to detect the presence of channels. The resolution of seismic data generally reaches 90 Hz. Spectral decomposition can produce outputs with up to 1 Hz intervals. The spectral components are correlated and repeated. To reduce the repetition of spectral data and increase the trend within the data, we use principal component spectral analysis. We apply and validate the workflow using the seismic data volume acquired over Boonsville, Texas, USA. The results of the cluster analysis method show good consistency with existing lithological maps interpreted from well data correlations.

Electrostatic frequency reduction: A negative stiffness mechanism for measuring dissipation in a mechanical oscillator at low frequency.

Broadband seismometers and gravitational wave detectors make use of mechanical resonators with a high quality factor to reduce Brownian noise. At low frequency, Brownian noise is ultimately dominated by internal friction in the suspension, which has a 1/f noise compared with the white noise arising from viscous dissipation. Internal friction is typically modeled as a frequency-dependent loss and can be challenging to measure reliably through experiment. In this work, we present the physics and experimental implementation of electrostatic frequency reduction (EFR) in a mechanical oscillator-a method to measure dissipation as a function of frequency. By applying a high voltage to two parallel capacitor plates, with the center plate being a suspended mass, an electrostatic force is created that acts as a negative stiffness mechanism to reduce the system's resonance frequency. Through EFR, the loss angle can be measured as a function of frequency by measuring amplitude decay response curves for a range of applied voltages. We present experimental measurements of the loss angle for three metal helical extension springs in the nominal frequency range 0.7-2.9 Hz at 0.2 Hz intervals, demonstrating the possibility for fine adjustment of the resonance frequency for loss angle measurements. A quality factor proportional to the resonance frequency squared was measured, an indication that internal friction and other non-viscous dissipation elements, such as electrostatic damping, were the prominent loss mechanisms in our experiments. Finally, we consider the implications of Brownian noise arising from internal friction on a low 1/f noise seismometer.

Engineering T cell response to cancer antigens by choice of focal therapeutic conditions

Focal thermal therapy (Heat), cryosurgery (Cryo) and irreversible electroporation (IRE) are increasingly used to treat cancer. However, local recurrence and systemic spread are persistent negative outcomes. Nevertheless, emerging work with immunotherapies (i.e., checkpoint blockade or dendritic cell (DC) vaccination) in concert with focal therapies may improve outcomes. To understand the role of focal therapy in priming the immune system for immunotherapy, an in vitro model of T cell response after exposure to B16 melanoma cell lysates after lethal exposures was designed. Exposure included: Heat (50 °C, 30 min), Cryo (−80 °C, 30 min) and IRE (1250 V/cm, 99 pulses, 50 µs pulses with 1 Hz intervals). After viability assessment (CCK-8 assay), cell lysates were collected and assessed for protein release (BCA assay), protein denaturation (FTIR-spectroscopy), TRP-2 antigen release (western blot), and T cell activation (antigen-specific CD8 T cell proliferation). Results showed IRE released the most protein and antigen (TRP-2), followed by Cryo and Heat. In contrast, Cryo released the most native (not denatured) protein, compared to IRE and Heat. Finally, IRE dramatically outperformed both Cryo and Heat in T cell activation while Cryo modestly outperformed Heat. This study demonstrates that despite all focal therapies ability to destroy cells, the ‘quantity’ (i.e., amount) and ‘quality’ (i.e., molecular state) of tumor protein (including antigen) released can dramatically change the ensuing priming of the immune system. This suggests protein-based metrics whereby focal therapies can be designed to prime the immune system in concert with immunotherapies to eventually achieve improved and durable cancer treatment in vivo.

Enhanced Water Removal from PEM Fuel Cells Using Acoustic Pressure Waves

Liquid water management remains a primary challenge in developing next generation low temperature proton exchange membrane fuel cells. This work demonstrates the use of acoustic pressure waves superimposed on reactant channel air flow as an effective means to enhance liquid water removal from gas diffusion layer surfaces. Experiments were conducted for a range of acoustic vibration frequencies; 20 to 120 Hz with 20 Hz intervals. Water transport was visualized using a CCD camera mounted over a transparent ex-situ PEM fuel cell test channel. Cumulative water areas were measured along the flow channel along with two-phase flow pressure drop for water fluxes of 400, 600, and 800 μℓ/h and a superficial air velocity of 1.82 m/s. Results show that superimposing acoustic pressure waves on the air flow can reduce liquid water build up and, therefore, reduce two-phase flow pressure drops. Cumulative water area was reduced almost 85% with an acoustic vibration frequency of 80 Hz compared to the 0 Hz case. Additionally, at 80 Hz the lowest two-phase flow pressure drop was recorded. Finally, a comparison of energy usage is made between different acoustic vibration application methods.

Impact of Subthalamic Deep Brain Stimulation Frequency on Upper Limb Motor Function in Parkinson's Disease.

Background:Whilst changes in the frequency of subthalamic deep brain stimulation (STN-DBS) have been proposed to improve control of tremor or axial motor features in Parkinson’s disease (PD), little is known about the effects of frequency changes on upper limb motor function, particularly bradykinesia.Objective:To investigate the acute effects of various STN-DBS frequencies (40–160 Hz, 40 Hz intervals) on upper limb motor function.Methods:We carried out a randomised, double-blind study on 20 PD patients with chronic STN-DBS using the Simple and Assembly components of the Purdue Pegboard (PP) test and a modified upper limb version of the UPDRS-III (UL-UPDRS-III).Results:There was no significant effect of frequency on bradykinesia on the Simple PP task or the UL-UPDRS-III. There was an effect of frequency on the Assembly PP score when comparing all frequencies (p = 0.019) and between 80 Hz and 130 Hz (p = 0.007), with lower frequencies yielding a better performance. Rigidity and Tremor scores were significantly reduced with higher (>80 Hz) compared to lower (40 Hz) frequencies.Conclusions:Our findings suggest that a wide range of frequencies are efficacious in improving acute upper-limb motor function. Reducing the frequency of stimulation down to 80 Hz is safe and has a similar clinical effect to higher frequencies. Therefore, a wider range of frequencies are available when it comes adjusting patients’ acute settings without the risk of worsening bradykinesia.

Investigating the BOLD spectral power of the intrinsic connectivity networks in fibromyalgia patients: A resting-state fMRI study.

Recent advances in multivariate statistical analysis of blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) have provided novel insights into the network organization of the human brain. Here, we applied group independent component analysis, a well-established approach for detecting brain intrinsic connectivity networks, to examine the spontaneous BOLD fluctuations in patients with fibromyalgia and healthy controls before and after exposure to a stressor. The BOLD spectral power characteristics of component time courses were calculated using the fast Fourier transform (FFT) algorithm, and group comparison was performed at six frequency bins between 0 and 0.24 Hz at 0.04 Hz intervals. Relative to controls, patients with fibromyalgia displayed significant BOLD spectral power differences in the default-mode, salience, and subcortical networks at the baseline level (PBon ferroni-corrected <; 0.05). Multivariate analysis of covariance (MANCOVA) further revealed significant effects of the cold water temperature, and pain rating on the spectral power of the sensorimotor, salience, and prefrontal networks, while the diagnosis of fibromyalgia influenced the BOLD spectral power of the salience and subcortical networks (PFDR-corrected <; 0.05). Since the BOLD spectral power reflects the degree of fluctuations within a network, future studies of the correlation between BOLD spectral power and pain processing can cast additional light on the nature of the central nervous system dysfunction in patients with chronic pain syndromes.

The determination of interseismic, coseismic and postseismic deformations caused by the Gökçeada-Samothraki earthquake (2014, Mw: 6.9) based on GNSS data

Since the 1990s, seismic deformations have been commonly determined using the Global Navigation Satellite System (GNSS). Recently, the GNSS systems have become even more powerful with the use of new technologies in innovative studies. In this study, the GNSS data was used to investigate interseismic, coseismic and postseismic deformation and velocity of the Gökçeada-Samothraki earthquake (Mw = 6.9) that occurred on May 24, 2014. The data was obtained at 30 s (0.033 Hz) and 1 s (1 Hz) intervals from the GNSS receivers in the network of Continuously Operating Reference Stations, Turkey (CORS-TR). For the interseismic period, the daily coordinate time series of 12 stations located within 90–250 km of the earthquake epicenter was evaluated for the displacement of stations over a period of approximately 2000 days prior to the day of the earthquakes, from October 1, 2008 to May 23, 2014. In order to analyze the ground motion displacement during the Gökçeada-Samothraki earthquake, 1 Hz data from 8 continuous GNSS stations was processed using precise point positioning (PPP) and relative positioning methods to estimate the epoch-by-epoch positions of the stations. During the earthquake, coseismic displacements of approximately 7 and 30 mm were detected in the NW direction at the YENC and CANA stations, respectively. However, at the IPSA station, a coseismic deformation of 20 mm was observed in the NE direction. There were no significant changes at the other stations during the earthquake. For the postseismic period, the daily coordinate time series of the 12 stations were evaluated for station displacements for 570 days after the day of the earthquakes, from May 24, 2014 to January 1, 2016. The results demonstrated that no significant postseismic deformation with the exception of the EDIR station. An abnormal deformation caused by local factors was determined at the EDIR station. In this study, the PPP and the relative solution were also compared in terms of capturing the earthquake wave motion. The results demonstrated that the PPP-based solutions showed good agreement with those of relative positioning in terms of the ability to capture coseismic displacement.

TU-FG-209-06: Quantitative Evaluation of the Temporal Performance of Clinical Fluoroscopic Imaging Systems: The Temporal Modulation Transfer Function (TMTF)

Purpose: Measure the temporal modulation transfer function (TMTF) of clinical fluoroscopic flat panel imaging systems in order to accurately quantify their performance for temporally sensitive clinical tasks. Methods: Copper blades (0.76 mm thick, 6 cm radius) with precision-machined edges were manufactured and mounted on a voltage regulated DC motor apparatus. Images were acquired with the blade apparatus positioned at the center of the detector matrix and set in motion at a constant rotational velocity (0.66 Hz), thereby creating a rotating radio-opaque edge in both space and time. The spatio-temporal edge response function was analyzed using a single frame from the acquired image sequence. Image processing included semi-automatic detection of the center of rotation, rebinning the pixels into subsampled polar coordinates, and deconvolving the TMTF from the previously measured spatial MTF. The analysis returned the presampled TMTF. This method was applied to multiple fluoroscopic imaging systems. Results: Initial experiments measured the TMTF of a typical fluoroscopy unit (Philips Allura Xper FD20) using cine acquisition (60.7 kVp, 6 fps, 42.6 ms pulse-width). For this system and protocol, the measured TMTF closely matched an idealized sinc function corresponding to the Fourier transform of the measured rectangular x-ray pulse-width. Within the frequency range of 0 – 47 Hz, the measured TMTF and ideal sinc function were compared at 1.46 Hz intervals. The differences measured varied within [-0.0164, 0.0324] with a root-mean-square (rms) difference of 0.0201. These particular results suggest that very little degradation in temporal performance is attributable to the imaging hardware, but rather the measured performance is dominated by the acquisition protocol parameters, namely pulse-width and frames-per-second. Conclusion: This method provides a clinically tractable and accurate measurement of the TMTF. Ongoing experiments are investigating the impact of different fluoroscopy systems, image processing, and protocol choice on the measured TMTF.

Oscillations of Skin Microvascular Blood Flow in Patients with Asthma.

This research is aimed at studying the features of skin blood flow oscillations in patients with severe persistent atopic BA during a period of fine control over symptoms. The study of microcirculation was carried out by LDF at rest and in response to a transient ischemia in 20 patients. The time-amplitude adaptive wavelet analysis of the blood flow oscillations was conducted to elucidate the peculiarities of microcirculatory regulation system functioning. No significant changes were revealed for SBP and the oscillation amplitudes in the cardiac (0.6-2 Hz) and respiratory (0.145-0.6 Hz) intervals, both at rest and in response to transient ischemia, in patients compared to the control group. A consistent twofold decrease in the oscillation amplitudes was found in the neurogenic (0.021-0.052 Hz) interval at rest, as well as in the myogenic (0.052-0.145 Hz) and NO-dependent endothelial (0.0095-0.021 Hz) intervals both at rest and during the postocclusive reactive hyperemia in patients with lung obstruction (FEV1 < 80%) in comparison with a control group. The amplitudes of skin blood flow oscillations in the myogenic, neurogenic and NO-dependent endothelial intervals in patients with obstruction are different from those in patients without obstruction.

Generational difference in the perception of high-toned [il] in Seoul Korean

A word-initial [il] is most frequently H-toned in Seoul Korean (SK) when it means one, out of three homophones, one, day, and work (Jun &amp; Cha, 2011). However, Cho (2014) finds that 25% of teenagers always produce [il] with a H tone, regardless of its meaning. This paper examines how young SK speakers perceive the phenomenon. Thirty-seven SK speakers (aged 14–29) participated in two identification tasks, hearing only [il] in the first task and four [il]-initial minimal pairs in the second task. All target words were manipulated into five pitch levels with 30 Hz intervals. In the first task, the 20s group identified [il] as one 70% of the time at higher pitch levels, while the teenagers identified [il] as one about 50% of the time at all pitch levels. In the second task, the 20s group showed a categorical perception, identifying [il]-initial words as one only at higher pitch levels, while the teenagers did not. The results suggest that the teenagers are aware that some peers always produce [il] with a H tone. It explains that the 20s group could identify the meanings of [il] depending on the pitch, while the teenagers could not.

Wavelet phase coherence analysis of the skin blood flow oscillations in human

The wavelet phase coherence of oscillations in the peripheral blood flow of contralateral skin sites was studied in 20 healthy subjects. Skin perfusion was registered simultaneously on similar regions of the outer sides of the right and left forearms by the laser Doppler flowmetry technique. To estimate the reliability of the obtained wavelet phase coherence values we applied the comparative method using amplitude-adjusted Fourier transform surrogates. High median values (0.63 and 0.59) of the wavelet phase coherence were obtained for the frequency intervals of respiratory (0.145–0.6Hz) and cardiac (0.6–2Hz) rhythms in 18 and 20 participants, respectively. In all the 20 participants we detected high and reliable values (Ме=0.72) of the wavelet phase coherence for skin blood flow oscillations in the myogenic interval (0.052–0.145Hz). Additionally, we demonstrated high wavelet phase coherence in the neurogenic (0.021–0.052Hz) and endothelial (0.0095–0.021Hz) intervals in 8 and 7 participants, respectively. The corresponding medians of the reliable wavelet phase coherence values for these intervals were 0.74 and 0.82. The obtained results suggest that the microvascular blood flow possesses not only the local mechanisms of generating low-frequency blood flow oscillations, but also a central mechanism, which is likely to synchronize low-frequency oscillations throughout the whole cardiovascular system.

AnEx VivoModel to Evaluate the Effect of Cyclical Adductory Forces on Maintenance of Arytenoid Abduction After Prosthetic Laryngoplasty Performed With and Without Mechanical Arytenoid Abduction

To (1) develop a model of cyclical adduction force on an abducted left arytenoid cartilage that mimics swallowing or coughing; (2) determine if arytenoid abduction by a clamp before knot tying will improve the maintenance of abduction under cyclical adduction testing. Experimental. Cadaveric equine larynges (n = 14). Left laryngoplasty performed using a single suture of #5 Ethibond with (n = 7) and without (n = 7) abducting the arytenoid with a clamp before knot tying. Each laryngoplasty was loaded cyclically from 2 to 26 N at 0.5 Hz for 5000 cycles in a servohydraulic test frame. Arytenoid displacement data were collected at 1 Hz intervals and median percent loss of abduction compared between groups. Significance was set at P < .05. Median left arytenoid abduction distance was 16.9 mm (range, 9.8-19.8 mm). One larynx in each group failed at <1000 cycles. Loss of abduction was determined by progressive displacement of the testing actuator and confirmed by measurement. There was no difference in loss of abduction between clamped and non-clamped larynges after 5000 cycles. This model of cyclical adduction resulted in arytenoid displacements similar to those seen in the 1st week postoperatively. Ex vivo cyclical adductory forces produced a significant loss of laryngoplasty abduction. The use of a clamp to abduct the arytenoid cartilage before knot tying did not reduce the loss of abduction.