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HIgh Frequency Oscillation

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https://www.readbyqxmd.com/read/28441393/sequence-learning-modulates-neural-responses-and-oscillatory-coupling-in-human-and-monkey-auditory-cortex
#1
Yukiko Kikuchi, Adam Attaheri, Benjamin Wilson, Ariane E Rhone, Kirill V Nourski, Phillip E Gander, Christopher K Kovach, Hiroto Kawasaki, Timothy D Griffiths, Matthew A Howard, Christopher I Petkov
Learning complex ordering relationships between sensory events in a sequence is fundamental for animal perception and human communication. While it is known that rhythmic sensory events can entrain brain oscillations at different frequencies, how learning and prior experience with sequencing relationships affect neocortical oscillations and neuronal responses is poorly understood. We used an implicit sequence learning paradigm (an "artificial grammar") in which humans and monkeys were exposed to sequences of nonsense words with regularities in the ordering relationships between the words...
April 2017: PLoS Biology
https://www.readbyqxmd.com/read/28441181/inhaled-treprostinil-drug-delivery-during-mechanical-ventilation-and-spontaneous-breathing-using-two-different-nebulizers
#2
Donna K Parker, Shuijie Shen, Jiang Zheng, D Dunbar Ivy, Dave N Crotwell, Justin C Hotz, Robert M DiBlasi
OBJECTIVES: To determine the feasibility of delivering inhaled treprostinil during mechanical ventilation and spontaneous unassisted ventilation using the Tyvaso Inhalation System and the vibrating mesh nebulizer. We sought to compare differences in fine particle fraction, and absolute inhaled treprostinil mass delivered to neonatal, pediatric, and adult models affixed with a face mask, conventional, and high-frequency ventilation between Tyvaso Inhalation System and with different nebulizer locations between Tyvaso Inhalation System and vibrating mesh nebulizer...
April 22, 2017: Pediatric Critical Care Medicine
https://www.readbyqxmd.com/read/28437979/30-hz-relative-linewidth-watt-output-power-1-65-%C3%A2%C2%B5m-continuous-wave-singly-resonant-optical-parametric-oscillator
#3
Aliou Ly, Christophe Siour, Fabien Bretenaker
We built a 1-watt cw singly resonant optical parametric oscillator operating at an idler wavelength of 1.65 µm for application to quantum interfaces. The non resonant idler is frequency stabilized by side-fringe locking on a relatively high-finesse Fabry-Perot cavity, and the influence of intensity noise is carefully analyzed. A relative linewidth down to the sub-kHz level (about 30 Hz over 2 s) is achieved. A very good long term stability is obtained for both frequency and intensity.
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28436151/whole-genome-sequence-association-and-ancestry-informed-polygenic-profile-of-eeg-alpha-in-a-native-american-population
#4
Qian Peng, Nicholas J Schork, Kirk C Wilhelmsen, Cindy L Ehlers
EEG alpha activity is the dominant oscillation in most adult humans, is highly heritable, and has been associated with a number of cognitive functions. Two EEG phenotypes, low- and high-voltage alpha (LVA & HVA), have been demonstrated to have high heritabilities. They have different prevalence depending on a population's ancestral origins. In the present study we assessed the influence of ancestry admixture on EEG alpha power, and conducted a whole genome sequencing association analysis and an ancestry-informed polygenic study on those phenotypes in a Native American (NA) population that has a high prevalence of LVA...
April 24, 2017: American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics
https://www.readbyqxmd.com/read/28435186/a-low-power-thermal-based-sensor-system-for-low-air-flow-detection
#5
Akm Arifuzzman, Mohammad Rafiqul Haider, David B Allison
Being able to rapidly detect a low air flow rate with high accuracy is essential for various applications in the automotive and biomedical industries. We have developed a thermal-based low air flow sensor with a low-power sensor readout for biomedical applications. The thermal-based air flow sensor comprises a heater and three pairs of temperature sensors that sense temperature differences due to laminar air flow. The thermal-based flow sensor was designed and simulated by using laminar flow, heat transfer in solids and fluids physics in COMSOL MultiPhysics software...
November 2016: Analog Integrated Circuits and Signal Processing
https://www.readbyqxmd.com/read/28432303/closed-loop-deep-brain-stimulation-by-pulsatile-delayed-feedback-with-increased-gap-between-pulse-phases
#6
Oleksandr V Popovych, Borys Lysyansky, Peter A Tass
Computationally it was shown that desynchronizing delayed feedback stimulation methods are effective closed-loop techniques for the control of synchronization in ensembles of interacting oscillators. We here computationally design stimulation signals for electrical stimulation of neuronal tissue that preserve the desynchronizing delayed feedback characteristics and comply with mandatory charge deposit-related safety requirements. For this, the amplitude of the high-frequency (HF) train of biphasic charge-balanced pulses used by the standard HF deep brain stimulation (DBS) is modulated by the smooth feedback signals...
April 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28432140/visually-evoked-3-5-hz-membrane-potential-oscillations-reduce-the-responsiveness-of-visual-cortex-neurons-in-awake-behaving-mice
#7
Michael C Einstein, Pierre-Olivier Polack, Duy T Tran, Peyman Golshani
Low frequency membrane potential (Vm) oscillations were once thought to only occur in sleeping and anesthetized states. Recently, low frequency Vm oscillations have been described in inactive awake animals, but it is unclear if they shape sensory processing in neurons and whether they occur during active awake behavioral states. To answer these questions, we performed two-photon guided whole-cell Vm recordings from primary visual cortex layer 2/3 excitatory and inhibitory neurons in awake mice during passive visual stimulation and performance of visual and auditory discrimination tasks...
April 21, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28430635/unsuccessful-mitosis-in-multicellular-tumour-spheroids
#8
Annie Molla, Morgane Couvet, Jean-Luc Coll
Multicellular spheroids are very attractive models in oncology because they mimic the 3D organization of the tumour cells with their microenvironment. We show here using 3 different cell types (mammary TSA/pc, embryonic kidney Hek293 and cervical cancer HeLa), that when the cells are growing as spheroids the frequency of binucleated cells is augmented as occurs in some human tumours.We therefore describe mitosis in multicellular spheroids by following mitotic markers and by time-lapse experiments. Chromosomes alignment appears to be correct on the metaphasic plate and the passenger complex is well localized on centromere...
February 24, 2017: Oncotarget
https://www.readbyqxmd.com/read/28430213/high-peak-power-hybrid-mopa-laser-with-tunable-pulse-repetition-frequency-and-pulse-duration
#9
Mingming Nie, Qiang Liu, Encai Ji, Xuezhe Cao, Fu Xing, Mali Gong
In this paper, we demonstrated a hybrid master oscillator power amplifier (MOPA) laser with high peak power and widely tunable pulse repetition frequency (PRF) and pulse duration. The first-stage solid-state amplifier was carefully designed to keep good beam quality and supply high gain simultaneously. The maximum peak power of 760 kW was achieved with average power of 42 W, PRF of 50 kHz, pulse duration of 1.1 ns, and near-diffraction limited beam quality. The MOPA laser covers a broad tunable temporal range with 1-100 ns for pulse duration and 50 kHz-1 MHz for PRF...
April 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/28430211/compact-high-power-high-beam-quality-quasi-cw-microsecond-five-pass-zigzag-slab-1319%C3%A2-%C3%A2-nm-amplifier
#10
Chuan Guo, Junwei Zuo, Qi Bian, Chang Xu, Qinshuang Zong, Yong Bo, Yu Shen, Nan Zong, Hongwei Gao, Yanyong Lin, Lei Yuan, Yang Liu, Dafu Cui, Qinjun Peng, Zuyan Xu
We demonstrate a compact, high-power, quasi-continuous-wave (QCW) end-pumped 1319 nm Nd:YAG slab amplifier laser with good beam quality. The laser is based on a QCW pulse Nd:YAG master oscillator and Nd:YAG slab amplifier with multi-pass zigzag architecture. The amplifier operates at a pulse repetition frequency of 500 Hz and pulse width of ∼105  μs, delivering a maximum output power of 51.5 W under absorbed pump power of 217.8 W and corresponding to an extraction efficiency of 14.2%. The beam quality factor is measured to be Mx2=1...
April 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/28424599/electrophysiological-sequelae-of-hemispherotomy-in-ipsilateral-human-cortex
#11
Ammar H Hawasli, Ravi Chacko, Nicholas P Szrama, David T Bundy, Mrinal Pahwa, Chester K Yarbrough, Brian J Dlouhy, David D Limbrick, Dennis L Barbour, Matthew D Smyth, Eric C Leuthardt
Objectives: Hemispheric disconnection has been used as a treatment of medically refractory epilepsy and evolved from anatomic hemispherectomy to functional hemispherectomies to hemispherotomies. The hemispherotomy procedure involves disconnection of an entire hemisphere with limited tissue resection and is reserved for medically-refractory epilepsy due to diffuse hemispheric disease. Although it is thought to be effective by preventing seizures from spreading to the contralateral hemisphere, the electrophysiological effects of a hemispherotomy on the ipsilateral hemisphere remain poorly defined...
2017: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/28424226/objective-measurement-of-adherence-to-out-patient-airway-clearance-therapy-by-high-frequency-chest-wall-compression-in-cystic-fibrosis
#12
Christina L Mikesell, Robert R Kempainen, Theresa A Laguna, Jeremiah S Menk, Andrew R Wey, Philippe R Gaillard, Warren E Regelmann
BACKGROUND: Objective measures of adherence to high-frequency chest wall compression (HFCWC, also known as high frequency chest wall oscillation, HFCWO), a form of airway clearance therapy for patients with cystic fibrosis, are lacking. We used a novel electronic monitoring device integrated into an HFCWC vest to measure adherence compared with self-reported adherence. We determined factors that influenced adherence and how adherence correlated with baseline pulmonary function and pulmonary exacerbations...
April 19, 2017: Respiratory Care
https://www.readbyqxmd.com/read/28420362/clinical-hemispheric-and-autonomic-changes-associated-with-use-of-closed-loop-allostatic-neurotechnology-by-a-case-series-of-individuals-with-self-reported-symptoms-of-post-traumatic-stress
#13
Charles H Tegeler, Jared F Cook, Catherine L Tegeler, Joshua R Hirsch, Hossam A Shaltout, Sean L Simpson, Brian C Fidali, Lee Gerdes, Sung W Lee
BACKGROUND: The objective of this pilot study was to explore the use of a closed-loop, allostatic, acoustic stimulation neurotechnology for individuals with self-reported symptoms of post-traumatic stress, as a potential means to impact symptomatology, temporal lobe high frequency asymmetry, heart rate variability (HRV), and baroreflex sensitivity (BRS). METHODS: From a cohort of individuals participating in a naturalistic study to evaluate use of allostatic neurotechnology for diverse clinical conditions, a subset was identified who reported high scores on the Posttraumatic Stress Disorder Checklist (PCL)...
April 19, 2017: BMC Psychiatry
https://www.readbyqxmd.com/read/28416442/allopregnanolone-decreases-interictal-spiking-and-fast-ripples-in-an-animal-model-of-mesial-temporal-lobe-epilepsy
#14
Maxime Lévesque, Rochelle Herrington, Leila Leclerc, Michael A Rogawski, Massimo Avoli
The objective of this study was to characterize the impact of allopregnanolone, a neurosteroid that acts as a positive allosteric modulator of synaptic and extrasynaptic GABAA receptors, on interictal spikes and high-frequency oscillations (ripples: 80-200 Hz, fast ripples: 250-500 Hz) in the pilocarpine model of mesial temporal lobe epilepsy. Seven out of 25 Sprague-Dawley rats experiencing 1 h of pilocarpine-induced status epilepticus (SE) began treatment with allopregnanolone (9.6-12.8 mg/kg/day) on the following day...
April 14, 2017: Neuropharmacology
https://www.readbyqxmd.com/read/28412559/interictal-ripples-nested-in-epileptiform-discharge-help-to-identify-the-epileptogenic-zone-in-neocortical-epilepsy
#15
Shuang Wang, Norman K So, Bo Jin, Irene Z Wang, Juan C Bulacio, Rei Enatsu, Shenyi Dai, Zhong Chen, Jorge Gonzalez-Martinez, Imad M Najm
OBJECTIVE: This study aimed to identify the subtype of interictal ripples that help delineate the epileptogenic zone in neocortical epilepsy. METHODS: Totally 25 patients with focal neocortical epilepsy who had invasive electroencephalography (EEG) evaluation and subsequent surgery were included. They were followed up for at least 2years. Interictal ripples (80-250Hz) and fast ripples (250-500Hz) during slow-wave sleep were identified. Neocortical ripples were defined as type I ripples when they were superimposed on epileptiform discharges, and as type II ripples when they occurred independently...
March 25, 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/28412092/chaotic-oscillations-of-gas-bubbles-under-dual-frequency-acoustic-excitation
#16
Yuning Zhang, Yuning Zhang
Chaotic oscillation of bubbles in liquids reduces the efficiency of the sonochemical system and should be suppressed in the practical applications. In the present paper, a chaos control method based on the dual-frequency approach is numerically investigated and is proved to be an effective method even for cases with intensive energy input. It was found that the chaos could be successfully suppressed by the application of dual-frequency approach in a wide range of parameter zone (even with high acoustic pressure amplitude)...
April 9, 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28411273/low-frequency-cortical-oscillations-entrain-to-sub-threshold-rhythmic-auditory-stimuli
#17
Sanne Ten Oever, Charles E Schroeder, David Poeppel, Nienke van Atteveldt, Ashesh D Mehta, Pierre Mégevand, David M Groppe, Elana Zion-Golumbic
Many environmental stimuli contain temporal regularities, a feature which can help predict forthcoming input. Phase-locking (entrainment) of ongoing low-frequency neuronal oscillations to rhythmic stimuli is proposed as a potential mechanism for enhancing neuronal responses and perceptual sensitivity, by aligning high-excitability phases to events within a stimulus stream. Previous experiments show that rhythmic structure has a behavioral benefit even when the rhythm itself is below perceptual detection thresholds (Ten Oever et al...
April 14, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28410534/comparison-of-operation-modes-for-spin-exchange-optically-pumped-spin-oscillators
#18
Zhiguo Wang, Xiang Peng, Hui Luo, Hong Guo
The nuclear spin precesses continually when a positive feedback nuclear magnetic resonance field is applied. The characteristics of this behaviour depend not only on the parameters of the spin ensemble but also on the type and parameters of the feedback loop. We theoretically analysed two types of feedback loops which use direct feedback and phase-lock feedback, respectively. We also compared the oscillating frequency of the spin oscillators using rotating and linear magnetic fields, respectively. Some interesting results on the frequency and start-time of the oscillator were found...
May 2017: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/28409815/high-frequency-continuous-birefringence-induced-oscillations-in-spin-polarized-vertical-cavity-surface-emitting-lasers
#19
M S Torre, H Susanto, Nianqiang Li, K Schires, M F Salvide, I D Henning, M J Adams, A Hurtado
Sustained, large amplitude and tunable birefringence-induced oscillations are obtained in a spin-vertical cavity surface-emitting laser (spin-VCSEL). Experimental evidence is provided using a spin-VCSEL operating at 1300 nm, under continuous-wave optical pumping and at room temperature. Numerical and stability analyses are performed to interpret the experiments and to identify the combined effects of pump ellipticity, spin relaxation rate, and cavity birefringence. Importantly, the frequency of the induced oscillations is determined by the device's birefringence rate, which can be tuned to very large values...
April 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28406919/what-are-the-assets-and-weaknesses-of-hfo-detectors-a-benchmark-framework-based-on-realistic-simulations
#20
Nicolas Roehri, Francesca Pizzo, Fabrice Bartolomei, Fabrice Wendling, Christian-George Bénar
High-frequency oscillations (HFO) have been suggested as biomarkers of epileptic tissues. While visual marking of these short and small oscillations is tedious and time-consuming, automatic HFO detectors have not yet met a large consensus. Even though detectors have been shown to perform well when validated against visual marking, the large number of false detections due to their lack of robustness hinder their clinical application. In this study, we developed a validation framework based on realistic and controlled simulations to quantify precisely the assets and weaknesses of current detectors...
2017: PloS One
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