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High Frequency Oscillations (high + frequency_oscillation)
Selected AbstractsThe effect of varying resistance or compliance on the movement of liquid during high frequency oscillationPEDIATRIC ANESTHESIA, Issue 6 2000R. O'Hare No abstract is available for this article. [source] Survey of neonatal respiratory support strategiesACTA PAEDIATRICA, Issue 8 2007Atul Sharma Abstract Aim: To survey current practice regarding neonatal respiratory support strategies to determine whether it reflected evidence from randomised trials. Methods: A questionnaire (in Supplementary Material online) survey of all U.K. neonatal units was undertaken to determine what modes of ventilation, types of endotracheal tube, lung function monitoring and oxygen saturation levels were used. Results: There was an 80% response rate. Most (73%) units used in prematurely born infants (in the first 24 h) the intermittent positive pressure ventilation, and other respiratory modes included: CPAP (2%), triggered ventilation with or without volume guarantee (22%) and high frequency oscillation (2%). Only 15% of units used assist control mode for weaning; the preferred weaning mode was synchronous intermittent mandatory ventilation (73%). Few units used shouldered endotracheal tubes (3%) or lung function measurements (25%) to aid choice of ventilator settings. Oxygen saturation levels from 80% to 98% were used, levels greater or equal to 95% were used by 11% of units for infants with acute respiratory disease but by 34% of units for BPD infants (p < 0.001). Conclusion: Many practitioners do not base their choice of neonatal respiratory support strategies on the results of large randomised trials; more effective methods are required to ensure evidence-based practice. [source] Coherence in consciousness: Paralimbic gamma synchrony of self-reference links conscious experiencesHUMAN BRAIN MAPPING, Issue 2 2010Hans C. Lou Abstract A coherent and meaningful percept of the world is essential for human nature. Consequently, much speculation has focused on how this is achieved in the brain. It is thought that all conscious experiences have reference to the self. Self-reference may either be minimal or extended, i.e., autonoetic. In minimal self-reference subjective experiences are self-aware in the weak sense that there is something it feels like for the subject to experience something. In autonoetic consciousness, consciousness emerges, by definition, by retrieval of memories of personally experienced events (episodic memory). It has been shown with transcranial magnetic stimulation (TMS) that a medial paralimbic circuitry is critical for self-reference. This circuitry includes anterior cingulate/medial prefrontal and posterior cingulate/medial parietal cortices, connected directly and via thalamus. We here hypothesized that interaction in the circuitry may bind conscious experiences with widely different degrees of self-reference through synchrony of high frequency oscillations as a common neural event. This hypothesis was confirmed with magneto-encephalography (MEG). The observed coupling between the neural events in conscious experience may explain the sense of unity of consciousness and the severe symptoms associated with paralimbic dysfunction. Hum Brain Mapp, 2010. © 2009 Wiley-Liss, Inc. [source] Electrophysiological evidence for altered early cerebral somatosensory signal processing in schizophreniaPSYCHOPHYSIOLOGY, Issue 3 2004Till D. Waberski Abstract Various studies have indicated an impairment of sensory signal processing in schizophrenic patients. Anatomical and functional imaging studies have indicated morphological and metabolic abnormalities in the thalamus in schizophrenia. Other results give evidence for an additional role of cortical dysfunction in sensory processing in schizophrenia. Advanced analysis of human median nerve somatosensory evoked potentials (SEPs) reveals a brief oscillatory burst of low-amplitude and high-frequency activity (,600 Hz), the so-called high frequency oscillations (HFOs). The present study explores the behavior of HFOs in a cohort of schizophrenic patients in comparison to a group of controls. HFOs in the group of patients appeared with a delayed latency. In the low-frequency part of the SEPs an increase in amplitude was found. These results are interpreted to reflect a lack of somatosensory inhibition in the somatosensory pathway, either at a thalamic or a cortical level. [source] Tuning in the transcriptome: basins of attraction in the yeast cell cycleCELL PROLIFERATION, Issue 4 2000R. R. Klevecz Image processing techniques and wavelet analyses have been applied to the yeast cell cycle expression microchip data to reveal large-scale temporally coherent structures and high frequency oscillations in mRNA levels through the cycle. Because transitions in expression frequently occur in phase, they appear as peaks or troughs in colour maps and contour plots of expression levels. Although apparent in the untreated data, these transitions were identified and enhanced by convolution of a Laplacian kernel with the expression arrays of the first 4096 genes. Transitions associated with maximum up- or down-regulation of mRNA levels appear as bands at 30,40 min intervals through two cell cycles. Time-frequency analyses using wavelet transforms support these visualization techniques and lead to the conclusion that, with respect to gene expression, the dominant period is not the cell cycle (90,120 min) but, more commonly, the higher frequency 30,40 minute submultiple of the cycle period. [source] | |||||||||||||