Search results for "FREQUENCY"

Statistical properties of the site-frequency spectrum associated with lambda-coalescents.

2013

Abstract Statistical properties of the site-frequency spectrum associated with Λ-coalescents are our objects of study. In particular, we derive recursions for the expected value, variance, and covariance of the spectrum, extending earlier results of Fu (1995) for the classical Kingman coalescent. Estimating coalescent parameters introduced by certain Λ-coalescents for data sets too large for full-likelihood methods is our focus. The recursions for the expected values we obtain can be used to find the parameter values that give the best fit to the observed frequency spectrum. The expected values are also used to approximate the probability a (derived) mutation arises on a branch subtending a…

Integration of local features into a global shape

2001

AbstractIt is a well-established fact that the cortical filters selective for spatial frequency and orientation have a limited spatial extent. The present study investigated how information from local filters is integrated into global shapes. Specifically, we were interested in whether identification of a global pattern consisting of small oriented, spatially-bandpass features (Gabor patches) depends on the orientations of those features. The observer was presented with a C-like stimulus shape comprised of oriented Gabor elements on a blank background, and the performance measure was the threshold contrast for identifying the global orientation of the C-shape (four possible rotated orientat…

The effect of resonance frequency breathing when used as a preparatory exercise in music psychotherapy : A single-case experimental study of a client…

2017

This study aimed at evaluating the possible benefits of starting Integrative Improvisational Music Therapy (IIMT) sessions with 10 min of Resonance Frequency Breathing (RFB), a type of slow breathing known to be beneficial for stress reduction and emotional regulation. A client diagnosed with anxiety disorder and social phobia attended 12 IIMT sessions. Using an alternating treatments design, RFB was systematically alternated with a control intervention (vibroacoustic therapy, VAT). Therapy processes were assessed through the Session Evaluation Questionnaire (SEQ) and the continuous measurement of heart rate variability (HRV), a biomarker of autonomic nervous system response. RFB was consis…

Effect of High-Frequency Oscillations on Cough Peak Flows Generated by Mechanical In-Exsufflation in Medically Stable Subjects With Amyotrophic Later…

2016

BACKGROUND: Mechanically assisted coughing with mechanical in-exsufflation (MI-E) is recommended for noninvasive management of respiratory secretions in amyotrophic lateral sclerosis (ALS). To improve the effectiveness of the technique, a new device combining MI-E with high-frequency oscillations (HFO) has been developed. This work aimed to assess the effect of HFO on the cough peak flow generated by MI-E in medically stable subjects with ALS. METHODS: This was a prospective study that included subjects with ALS in a medically stable condition. Cough peak flow generated by MI-E was measured in 4 situations: without HFO, with HFO during insufflation, with HFO during exsufflation, and with HF…

Noninvasive oscillatory ventilation (NHFOV) in infants: Another brick in the wall of paediatric noninvasive ventilation?

2016

EDITORIAL

Noninvasive oscillatory ventilation (NHFOV) in infants: Another brick in the wall of paediatric noninvasive ventilation?

2016

Is a 1-cm margin from major vessels adequate for radiofrequency ablation of pulmonary neoplasms?

2009

A powerful thyristor modulator for a microtron

1980

Abstract The circuit of a powerful modulator is illustrated and a detailed description is given of the modulator construction and in particular of the components employed. The main parameters are: length of shaped pulse 2 μs; amplitude of the output voltage 30 kV; pulse repetition frequency 50–200 Hz. The compactness of this device, its comparatively low cost and its good performance, as illustrated in the attached photographs, make it suitable for use in accelerator engineering (microtron).

Sub-200-kHz single soliton generation in a long ring Er-fiber laser with strict polarization control by using twisted fiber

2020

Abstract In the present work we demonstrate a novel single-soliton ultra-low pulse repetition frequency passively mode-locked erbium-doped fiber laser. We mitigate the residual linear birefringence of fiber by fiber twist to achieve a strict control of polarization. For mode-locking the nonlinear polarization rotation (NPR) was used. Special technique was applied to reduce the overdriving of NPR that allows the generation of single soliton in ultra-long cavity. The strict control of polarization yields a stable relation between the polarization state of the pulses propagating in the cavity and the regimes of generation. A 192.12-kHz train of soliton pulses was obtained with pulse duration o…

Assessment of a Modified Acoustic Lens for Electromagnetic Shock Wave Lithotripters in a Swine Model

2013

The acoustic lens of the Modularis electromagnetic shock wave lithotripter (Siemens, Malvern, Pennsylvania) was modified to produce a pressure waveform and focal zone more closely resembling that of the original HM3 device (Dornier Medtech, Wessling, Germany). We assessed the newly designed acoustic lens in vivo in an animal model.Stone fragmentation and tissue injury produced by the original and modified lenses of the Modularis lithotripter were evaluated in a swine model under equivalent acoustic pulse energy (about 45 mJ) at 1 Hz pulse repetition frequency. Stone fragmentation was determined by the weight percent of stone fragments less than 2 mm. To assess tissue injury, shock wave trea…