Search results for "frequency"
showing 10 items of 2158 documents
Does the origin of ablated premature ventricular contractions determine the level of left ventricular function improvement?
2020
Background: Premature ventricular contractions (PVCs) are associated with tachycardiomyopathy and high mortality rate. The treatment depends on the engaged ventricle. For PVCs originating from the right outflow tract (OT), radiofrequency catheter ablation (RFCA) is recommended (class IB‑R recommendation) in preference to pharmacotherapy. In those originating from the left ventricle, ablation is a class IIa B‑NR recommendation. Aims: The aim of the study was to assess the success of RFCA of PVCs based on arrhythmia origin. Methods: A total of 110 consecutive patients with monomorphic PVCs referred for ablation were enrolled and divided according to the site of ablation to the OT group and th…
Ultrasound-induced blood clot dissolution without a thrombolytic drug is more effective with lower frequencies.
2004
<i>Background and Purpose:</i> Therapeutic ultrasound as stand-alone therapy or in combination with rt-PA has proven to be an effective measure for recanalisation of acute vessel occlusion in different in vitro and in vivo studies. Uncertainty still exists concerning the optimal frequency and intensity with regard to the thrombolytic efficacy of ultrasound. The purpose of this study was a direct comparison of different ultrasound frequencies, when otherwise using identical measurement settings and parameters. <i>Methods:</i> Ultrasound-induced dissolution of fresh human blood clots was studied in a flow system using low-frequency continuous wave ultrasound of 20, 40 …
Individual alpha peak frequency, an important biomarker for live Z-Score training neurofeedback in adolescents with learning disabilities
2021
Learning disabilities (LDs) have an estimated prevalence between 5% and 9% in the pediatric population and are associated with difficulties in reading, arithmetic, and writing. Previous electroencephalography (EEG) research has reported a lag in alpha-band development in specific LD phenotypes, which seems to offer a possible explanation for differences in EEG maturation. In this study, 40 adolescents aged 10–15 years with LDs underwent 10 sessions of Live Z-Score Training Neurofeedback (LZT-NF) Training to improve their cognition and behavior. Based on the individual alpha peak frequency (i-APF) values from the spectrogram, a group with normal i-APF (ni-APF) and a group with low i-APF (li-…
Enhancing improvisational music therapy through the addition of resonance frequency breathing : Common findings of three single-case experimental stu…
2018
One core characteristic of active music therapy is the facilitation of emotional expression through the creation of music improvisations. In an attempt to further develop this approach, we created an enhanced form of integrative improvisational music therapy by including 10 minutes of resonance frequency breathing (RFB) at the beginning of the sessions. RFB is a type of slowbreathing known for its ability to reduce stress and support emotional regulation. This paper summarizes the common findings of three single-case experimental studies and introduces a provisional model to explain the observed effects of RFB. During the breathing itself, all three clients (two of them healthy and one diag…
Absence of the lactase-persistence-associated allele in early Neolithic Europeans.
2007
Lactase persistence (LP), the dominant Mendelian trait conferring the ability to digest the milk sugar lactose in adults, has risen to high frequency in central and northern Europeans in the last 20,000 years. This trait is likely to have conferred a selective advantage in individuals who consume appreciable amounts of unfermented milk. Some have argued for the “culture-historical hypothesis,” whereby LP alleles were rare until the advent of dairying early in the Neolithic but then rose rapidly in frequency under natural selection. Others favor the “reverse cause hypothesis,” whereby dairying was adopted in populations with preadaptive high LP allele frequencies. Analysis based on the cons…
Frequency of polymorphisms of signal peptide of TGF-beta1 and -1082G/A SNP at the promoter region of Il-10 gene in patients with carotid stenosis
2006
The role of inflammation in atherosclerosis is well recognized. We have evaluated the allele frequencies of the +869T/C and +915G/C polymorphisms (SNPs) at the TGF-beta1 gene and -1082G/A SNP at IL-10 promoter sequence, two well-known immunosuppressive and anti-inflammatory cytokines, in patients with carotid stenosis. Our data suggest a lack of association between these SNPs and the susceptibility to atherosclerosis although other reports have demonstrated this association. These results may be due to the pleiotropic effects of the cytokines and/or differences in haplotype combination that should be investigated to elucidate the role of TGF-beta1 and IL-10 polymorphisms in atherosclerosis.
Reproducibility and validity of a food frequency questionnaire among pregnant women in a Mediterranean area
2013
Background: Studies exploring the role of diet during pregnancy are still scarce, in part due to the complexity of measuring diet and to the lack of valid instruments. The aim of this study was to examine the reproducibility and validity (against biochemical biomarkers) of a semi-quantitative food frequency questionnaire (FFQ) in pregnant women. Methods: Participants were 740 pregnant women from a population-based birth cohort study in Valencia (INMA Study). We compared nutrient and food intakes from FFQs estimated for two periods of pregnancy (reproducibility), and compared energy-adjusted intake of several carotenoids, folate, vitamin B12, vitamin C and a-tocopherol of the FFQ in the firs…
A Velocity Estimation Technique for a Monocular Camera Using mmWave FMCW Radars
2021
Perception in terms of object detection, classification, and dynamic estimation (position and velocity) are fundamental functionalities that autonomous agents (unmanned ground vehicles, unmanned aerial vehicles, or robots) have to navigate safely and autonomously. To date, various sensors have been used individually or in combination to achieve this goal. In this paper, we present a novel method for leveraging millimeter wave radar’s (mmW radar’s) ability to accurately measure position and velocity in order to improve and optimize velocity estimation using a monocular camera (using optical flow) and machine learning techniques. The proposed method eliminates ambiguity in optical flow veloci…
Enhancing the performance of HSDPA communication with multipoint transmission techniques
2015
The evolution of mobile phones, tablets and other mobile communication devices has led to a significant increase in the amount of data delivered over mobile networks. In order to satisfy the climbing data rate demands of customers, existing mobile broadband networks are being expanded with new features that allow ubiquitous and consistent networking experience. This research presents three multipoint transmission techniques for Wideband Code Division Multiple Access (WCDMA) based High-Speed Downlink Packet Access (HSDPA) communication protocol. Multiflow, High-Speed Single-Frequency Network (HS-SFN) and Multipoint-to-Point Single-Frequency Network (M2P-SFN) enable transmission of user-dedicat…
Design and Performance Evaluation of a High Power-Density EMI Filter for PWM Inverter-Fed Induction-Motor Drives
2016
This paper presents the design of an electromagnetic interference (EMI) filter for a low-voltage high-current induction-motor drives supplied by dc power grids. In order to effectively design the EMI filter, a suitable common-mode/differential-mode (CM/DM) separation technique has been used. Due to the high operating currents, the software-based separation technique using time-domain measurements has been applied. The proposed technique allows the CM and DM sections of the EMI filter to be properly selected in a more economical way, i.e., without the need of a dedicated hardware or costly radio frequency (RF) instrumentation. The design has been done according to a power-density criterion. …