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https://www.readbyqxmd.com/read/28527912/implicit-variations-of-temporal-predictability-shaping-the-neural-oscillatory-and-behavioural-response
#1
Sophie K Herbst, Jonas Obleser
Being able to predict when an event will occur (temporal predictability) can help us prepare and time our responses. We here sought to delineate the neural and behavioural corollaries of highly implicit, probabilistic temporal predictability in an auditory foreperiod paradigm. To this end, we measured electroencephalography (EEG) and response times in two independent experiments (total N = 46). Unbeknownst to participants, we induced a probabilistic variation of cue-target delays (i.e., foreperiods) in a pitch-discrimination task on a noise-embedded tone: The smaller the standard deviation of the underlying foreperiod distribution, the more predictable the time of target occurrence should be...
May 17, 2017: Neuropsychologia
https://www.readbyqxmd.com/read/28527439/preferential-binding-effects-on-protein-structure-and-dynamics-revealed-by-coarse-grained-monte-carlo-simulation
#2
R B Pandey, D J Jacobs, B L Farmer
The effect of preferential binding of solute molecules within an aqueous solution on the structure and dynamics of the histone H3.1 protein is examined by a coarse-grained Monte Carlo simulation. The knowledge-based residue-residue and hydropathy-index-based residue-solvent interactions are used as input to analyze a number of local and global physical quantities as a function of the residue-solvent interaction strength (f). Results from simulations that treat the aqueous solution as a homogeneous effective solvent medium are compared to when positional fluctuations of the solute molecules are explicitly considered...
May 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28527204/levetiracetam-alters-oscillatory-connectivity-in-alzheimer-s-disease
#3
Christian S Musaeus, Mouhsin M Shafi, Emiliano Santarnecchi, Susan T Herman, Daniel Z Press
Seizures occur at a higher frequency in people with Alzheimer's disease (AD) but overt, clinically obvious events are infrequent. Evidence from animal models and studies in mild cognitive impairment suggest that subclinical epileptic discharges may play a role in the clinical and pathophysiological manifestations of AD. In this feasibility study, the neurophysiological and cognitive effects of acute administration of levetiracetam (LEV) are measured in patients with mild AD to test whether it could have a therapeutic benefit...
May 17, 2017: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/28526621/electrophysiological-signatures-of-phonological-and-semantic-maintenance-in-sentence-repetition
#4
Jed A Meltzer, Aneta Kielar, Lilia Panamsky, Kira A Links, Tiffany Deschamps, Rosie C Leigh
Verbal short-term memory comprises resources for phonological rehearsal, which have been characterized anatomically, and for maintenance of semantic information, which are less understood. Sentence repetition tasks tap both processes interactively. To distinguish brain activity involved in phonological vs. semantic maintenance, we recorded magnetoencephalography during a sentence repetition task, incorporating three manipulations emphasizing one mechanism over the other. Participants heard sentences or word lists and attempted to repeat them verbatim after a 5-second delay...
May 16, 2017: NeuroImage
https://www.readbyqxmd.com/read/28525548/computational-fluid-dynamics-characterization-of-pulsatile-flow-in-central-and-sano-shunts-connected-to-the-pulmonary-arteries-importance-of-graft-angulation-on-shear-stress-induced-platelet-mediated-thrombosis
#5
Robert Ascuitto, Nancy Ross-Ascuitto, Martin Guillot, Carey Celestin
OBJECTIVES: Central (aorta) and Sano (right ventricle)-to-pulmonary artery (PA) shunts, palliative operations for infants with complex heart defects, can develop life-threatening thrombosis. We employed computational fluid dynamics (CFD) to study pulsatile flow in these shunts, with the goal to identify haemodynamic characteristics conducive to thrombus formation. METHODS: CFD, using the finite volume method with cardiac catheterization data, and computer simulations, based on angiography, were employed to determine flow-velocity field, wall shear stress (WSS) profile and oscillatory shear index (OSI)...
May 19, 2017: Interactive Cardiovascular and Thoracic Surgery
https://www.readbyqxmd.com/read/28524913/periodic-oscillation-of-ion-conduction-of-nanofluidic-diodes-using-a-chemical-oscillator
#6
Huacheng Zhang, Jue Hou, Ranwen Ou, Yaoxin Hu, Huanting Wang, Lei Jiang
Periodic ion-conduction oscillation of biological ion channels in a living system is essential for numerous life processes. Here we report an oscillatory nanofluidic system that can self-regulate its ion-conduction states under constant conditions. The oscillatory nanofluidic system is constructed by integrating a chemical oscillator into an artificial single nanochannel system. Oscillating chemical reactions of the pH oscillator carried out inside the nanochannel are used to switch the surface properties of the channel between highly and lowly charged states, thus realizing an autonomous, continuous and periodic oscillation of the ion conductance of the channel between high and low ion-conduction states...
May 19, 2017: Nanoscale
https://www.readbyqxmd.com/read/28524701/helical-water-wires
#7
A R Liboff, C Poggi, P Pratesi
A helitetrahedral model has been proposed to help explain reports of low-frequency oscillations in pure water following electromagnetic excitation at the hydronium ion cyclotron resonance frequency. The Lorentz force and the intrinsic structure constrain the motion of the H3O(+) ion so that it enjoys a unique form of proton-hopping, one whose path is helical. This model may also explain the numerous previously observed cyclotron resonance (ICR) biological couplings for cations other than hydronium by merely substituting hydrogen-bonded versions of these for hydronium in the tetrahedral structure...
May 19, 2017: Electromagnetic Biology and Medicine
https://www.readbyqxmd.com/read/28524687/observation-of-oscillatory-radial-electric-field-relaxation-in-a-helical-plasma
#8
J A Alonso, E Sánchez, I Calvo, J L Velasco, K J McCarthy, A Chmyga, L G Eliseev, T Estrada, R Kleiber, L I Krupnik, A V Melnikov, P Monreal, F I Parra, S Perfilov, A I Zhezhera
Measurements of the relaxation of a zonal electrostatic potential perturbation in a nonaxisymmetric magnetically confined plasma are presented. A sudden perturbation of the plasma equilibrium is induced by the injection of a cryogenic hydrogen pellet in the TJ-II stellarator, which is observed to be followed by a damped oscillation in the electrostatic potential. The waveform of the relaxation is consistent with theoretical calculations of zonal potential relaxation in a nonaxisymmetric magnetic geometry. The turbulent transport properties of a magnetic confinement configuration are expected to depend on the features of the collisionless damping of zonal flows, of which the present Letter is the first direct observation...
May 5, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28524673/detecting-gravitational-wave-memory-without-parent-signals
#9
Lucy O McNeill, Eric Thrane, Paul D Lasky
Gravitational-wave memory manifests as a permanent distortion of an idealized gravitational-wave detector and arises generically from energetic astrophysical events. For example, binary black hole mergers are expected to emit memory bursts a little more than an order of magnitude smaller in strain than the oscillatory parent waves. We introduce the concept of "orphan memory": gravitational-wave memory for which there is no detectable parent signal. In particular, high-frequency gravitational-wave bursts (≳kHz) produce orphan memory in the LIGO/Virgo band...
May 5, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28524011/effects-of-heating-and-calcium-and-phosphate-mineral-supplementation-on-the-physical-properties-of-rennet-induced-coagulation-of-camel-and-cow-milk-gels
#10
Mohammad Kamal, Mohammed Foukani, Romdhane Karoui
The physical properties of rennet-induced coagulation of preheated camel and cow milk gels (50 and 70 °C for 10 min) enriched with calcium chloride (CaCl2) and hydrogen phosphate dihydrate (Na2HPO42H2O) were evaluated using the dynamic low amplitude oscillatory shear analysis. The storage modulus (G') and loss modulus (G") of camel milk gels showed significant (P < 0·05) lower values than those of cow milk gels. The preheating of camel milk at 50 °C affected negatively the gelation properties, while the preheating at 70 °C prevented the formation of rennet-induced milk gels...
May 2017: Journal of Dairy Research
https://www.readbyqxmd.com/read/28523456/bone-marrow-mesenchymal-stem-cell-administration-significantly-improves-outcome-after-retinal-ischemia-in-rats
#11
Biji Mathew, Jacqueline N Poston, John C Dreixler, Leianne Torres, Jasmine Lopez, Ruth Zelkha, Irina Balyasnikova, Maciej S Lesniak, Steven Roth
PURPOSE: Ischemia-associated retinal degeneration is one of the leading causes of vision loss, and to date, there are no effective treatment options. We hypothesized that delayed injection of bone-marrow stem cells (BMSCs) 24 h after the onset of ischemia could effectively rescue ischemic retina from its consequences, including apoptosis, inflammation, and increased vascular permeability, thereby preventing retinal cell loss. METHODS: Retinal ischemia was induced in adult Wistar rats by increasing intraocular pressure (IOP) to 130-135 mmHg for 55 min...
May 18, 2017: Graefe's Archive for Clinical and Experimental Ophthalmology
https://www.readbyqxmd.com/read/28522983/a-dynamical-model-of-pitch-memory-provides-an-improved-basis-for-implied-harmony-estimation
#12
Ji Chul Kim
Tonal melody can imply vertical harmony through a sequence of tones. Current methods for automatic chord estimation commonly use chroma-based features extracted from audio signals. However, the implied harmony of unaccompanied melodies can be difficult to estimate on the basis of chroma content in the presence of frequent nonchord tones. Here we present a novel approach to automatic chord estimation based on the human perception of pitch sequences. We use cohesion and inhibition between pitches in auditory short-term memory to differentiate chord tones and nonchord tones in tonal melodies...
2017: Frontiers in Psychology
https://www.readbyqxmd.com/read/28522836/dynamics-of-oscillators-globally-coupled-via-two-mean-fields
#13
Xiyun Zhang, Arkady Pikovsky, Zonghua Liu
Many studies of synchronization properties of coupled oscillators, based on the classical Kuramoto approach, focus on ensembles coupled via a mean field. Here we introduce a setup of Kuramoto-type phase oscillators coupled via two mean fields. We derive stability properties of the incoherent state and find traveling wave solutions with different locking patterns; stability properties of these waves are found numerically. Mostly nontrivial states appear when the two fields compete, i.e. one tends to synchronize oscillators while the other one desynchronizes them...
May 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28522346/seeing-in-the-dark-phosphene-thresholds-with-eyes-open-versus-closed-in-the-absence-of-visual-inputs
#14
T A de Graaf, F Duecker, Y Stankevich, S Ten Oever, A T Sack
BACKGROUND: Voluntarily opening or closing our eyes results in fundamentally different input patterns and expectancies. Yet it remains unclear how our brains and visual systems adapt to these ocular states. OBJECTIVE/HYPOTHESIS: We here used transcranial magnetic stimulation (TMS) to probe the excitability of the human visual system with eyes open or closed, in the complete absence of visual inputs. METHODS: Combining Bayesian staircase procedures with computer control of TMS pulse intensity allowed interleaved determination of phosphene thresholds (PT) in both conditions...
May 3, 2017: Brain Stimulation
https://www.readbyqxmd.com/read/28522331/internal-mechanisms-underlying-anticipatory-language-processing-evidence-from-event-related-potentials-and-neural-oscillations
#15
Xiaoqing Li, Yuping Zhang, Jinyan Xia, Tamara Y Swaab
Although numerous studies have demonstrated that the language processing system can predict upcoming content during comprehension, there is still no clear picture of the anticipatory stage of predictive processing. This electroencephalograph study examined the cognitive and neural oscillatory mechanisms underlying anticipatory processing during language comprehension, and the consequences of this prediction for bottom-up processing of predicted/unpredicted content. Participants read Mandarin Chinese sentences that were either strongly or weakly constraining and that contained critical nouns that were congruent or incongruent with the sentence contexts...
May 15, 2017: Neuropsychologia
https://www.readbyqxmd.com/read/28521155/is-laughter-a-better-vocal-change-detector-than-a-growl
#16
Ana P Pinheiro, Carla Barros, Margarida Vasconcelos, Christian Obermeier, Sonja A Kotz
The capacity to predict what should happen next and to minimize any discrepancy between an expected and an actual sensory input (prediction error) is a central aspect of perception. Particularly in vocal communication, the effective prediction of an auditory input that informs the listener about the emotionality of a speaker is critical. What is currently unknown is how the perceived valence of an emotional vocalization affects the capacity to predict and detect a change in the auditory input. This question was probed in a combined event-related potential (ERP) and time-frequency analysis approach...
April 11, 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
https://www.readbyqxmd.com/read/28521049/22q11-2-deletion-syndrome-is-associated-with-impaired-auditory-steady-state-gamma-response
#17
Kit Melissa Larsen, Giovanni Pellegrino, Michelle Rosgaard Birknow, Trine Nørgaard Kjær, William Frans Christiaan Baaré, Michael Didriksen, Line Olsen, Thomas Werge, Morten Mørup, Hartwig Roman Siebner
Background: The 22q11.2 deletion syndrome confers a markedly increased risk for schizophrenia. 22q11.2 deletion carriers without manifest psychotic disorder offer the possibility to identify functional abnormalities that precede clinical onset. Since schizophrenia is associated with a reduced cortical gamma response to auditory stimulation at 40 Hz, we hypothesized that the 40 Hz auditory steady-state response (ASSR) may be attenuated in nonpsychotic individuals with a 22q11.2 deletion...
May 17, 2017: Schizophrenia Bulletin
https://www.readbyqxmd.com/read/28515420/vascular-remodelling-relates-to-an-elevated-oscillatory-shear-index-and-relative-residence-time-in-spontaneously-hypertensive-rats
#18
Zhiyan Chen, Haiyi Yu, Yue Shi, Minjia Zhu, Yueshen Wang, Xi Hu, Youyi Zhang, Yu Chang, Ming Xu, Wei Gao
Haemodynamic disorders are common clinical findings in hypertension and lead to adverse cardiovascular events. However, the haemodynamic conditions in hypertension models are poorly understood. This study aimed to observe the characteristics of haemodynamics in spontaneously hypertensive rats (SHRs) and antihypertensive-treated SHRs. Twenty-four adult male SHRs and Wistar-Kyoto rats (WKYs) were randomly divided into four groups and treated for 7 days as follows: WKY-CON (WKYs + saline), WKY-NIF (WKYs + nifedipine, 50 mg/kg/day), SHR-CON (SHRs + saline), and SHR-NIF (SHRs + nifedipine)...
May 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28515328/mechanotransmission-in-endothelial-cells-subjected-to-oscillatory-and-multi-directional-shear-flow
#19
Mahsa Dabagh, Payman Jalali, Peter J Butler, Amanda Randles, John M Tarbell
Local haemodynamics are linked to the non-uniform distribution of atherosclerosic lesions in arteries. Low and oscillatory (reversing in the axial flow direction) wall shear stress (WSS) induce inflammatory responses in endothelial cells (ECs) mediating disease localization. The objective of this study is to investigate computationally how the flow direction (reflected in WSS variation on the EC surface over time) influences the forces experienced by structural components of ECs that are believed to play important roles in mechanotransduction...
May 2017: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/28512444/longitudinal-quantification-of-eye-movement-impairments-after-pontine-hemorrhage
#20
Melis Suner, Glen T Prusky, Jason B Carmel, N Jeremy Hill
INTRODUCTION: We report a case of hypertrophic olivary degeneration due to pontine hemorrhage. A 59-year-old male with untreated hypertension suffered a primary pontine hemorrhage, which caused horizontal eye-movement limitation. Progressive neurological deterioration with involuntary eye and palatal movements began months after hemorrhage. This was accompanied by magnetic resonance imaging evidence of hypertrophic olivary degeneration at 4.5 months. BACKGROUND: Primary pontine hemorrhage often leads to impairment of eye movements and diplopia...
2017: Frontiers in Neurology
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