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Cross frequency coupling

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https://www.readbyqxmd.com/read/28821753/dynamic-reconfiguration-of-cortical-functional-connectivity-across-brain-states
#1
Iain Stitt, Karl J Hollensteiner, Edgar Galindo-Leon, Florian Pieper, Eva Fiedler, Thomas Stieglitz, Gerhard Engler, Guido Nolte, Andreas K Engel
Throughout each day, the brain displays transient changes in state, as evidenced by shifts in behavior and vigilance. While the electrophysiological correlates of brain states have been studied for some time, it remains unclear how large-scale cortico-cortical functional connectivity systematically reconfigures across states. Here, we investigate state-dependent shifts in cortical functional connectivity by recording local field potentials (LFPs) during spontaneous behavioral transitions in the ferret using chronically implanted micro-electrocorticographic (µECoG) arrays positioned over occipital, parietal, and temporal cortical regions...
August 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28798683/enhanced-gamma-activity-and-cross-frequency-interaction-of-resting-state-electroencephalographic-oscillations-in-patients-with-alzheimer-s-disease
#2
Jing Wang, Yuxing Fang, Xiao Wang, Huichao Yang, Xin Yu, Huali Wang
Cognitive impairment, functional decline and behavioral symptoms that characterize Alzheimer's disease (AD) are associated with perturbations of the neuronal network. The typical electroencephalographic (EEG) features in AD patients are increased delta or theta rhythm and decreased alpha or beta rhythm activities. However, considering the role of cross-frequency couplings in cognition, the alternation of cross-frequency couplings in AD patients is still obscure. This study aims to explore the interaction dynamics between different EEG oscillations in AD patients...
2017: Frontiers in Aging Neuroscience
https://www.readbyqxmd.com/read/28790178/heteromeric-channels-formed-by-trpc1-trpc4-and-trpc5-define-hippocampal-synaptic-transmission-and-working-memory
#3
Jenny Bröker-Lai, Astrid Kollewe, Barbara Schindeldecker, Jörg Pohle, Vivan Nguyen Chi, Ilka Mathar, Raul Guzman, Yvonne Schwarz, Alan Lai, Petra Weißgerber, Herbert Schwegler, Alexander Dietrich, Martin Both, Rolf Sprengel, Andreas Draguhn, Georg Köhr, Bernd Fakler, Veit Flockerzi, Dieter Bruns, Marc Freichel
Canonical transient receptor potential (TRPC) channels influence various neuronal functions. Using quantitative high-resolution mass spectrometry, we demonstrate that TRPC1, TRPC4, and TRPC5 assemble into heteromultimers with each other, but not with other TRP family members in the mouse brain and hippocampus. In hippocampal neurons from Trpc1/Trpc4/Trpc5-triple-knockout (Trpc1/4/5(-/-)) mice, lacking any TRPC1-, TRPC4-, or TRPC5-containing channels, action potential-triggered excitatory postsynaptic currents (EPSCs) were significantly reduced, whereas frequency, amplitude, and kinetics of quantal miniature EPSC signaling remained unchanged...
August 8, 2017: EMBO Journal
https://www.readbyqxmd.com/read/28757194/time-resolved-phase-amplitude-coupling-in-neural-oscillations
#4
Soheila Samiee, Sylvain Baillet
Cross-frequency coupling between neural oscillations is a phenomenon observed across spatial scales in a wide range of preparations, including human non-invasive electrophysiology. Although the functional role and mechanisms involved are not entirely understood, the concept of interdependent neural oscillations drives an active field of research to comprehend the ubiquitous polyrhythmic activity of the brain, beyond empirical observations. Phase-amplitude coupling, a particular form of cross-frequency coupling between bursts of high-frequency oscillations and the phase of lower frequency rhythms, has recently received considerable attention...
July 27, 2017: NeuroImage
https://www.readbyqxmd.com/read/28737378/quantitative-mid-infrared-cavity-ringdown-detection-of-methyl-iodide-for-monitoring-applications
#5
Ibrahim Sadiek, Qiang Shi, Douglas W R Wallace, Gernot Friedrichs
Methyl iodide is a toxic halocarbon with diverse industrial and agricultural applications, and it is an important ocean-derived trace gas that contributes to the iodine burden of the atmosphere. Quantitative analysis of CH3I is mostly based on gas chromatography coupled with mass spectrometry or electron capture detection (GC-MS/ECD) as of yet, which often limits the ability to conduct in situ high-frequency monitoring studies. This work presents an alternative detection scheme based on mid-infrared continuous wave cavity ringdown spectroscopy (mid-IR cw-CRDS)...
August 4, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28735144/entorhinal-tau-pathology-disrupts-hippocampal-prefrontal-oscillatory-coupling-during-associative-learning
#6
Stephanie E Tanninen, Bardia Nouriziabari, Mark D Morrissey, Rami Bakir, Robert D Dayton, Ronald L Klein, Kaori Takehara-Nishiuchi
A neural signature of asymptomatic preclinical Alzheimer's disease (AD) is disrupted connectivity between brain regions; however, its underlying mechanisms remain unknown. Here, we tested whether a preclinical pathologic feature, tau aggregation in the entorhinal cortex (EC) is sufficient to disrupt the coordination of local field potentials (LFPs) between its efferent regions. P301L-mutant human tau or green fluorescent protein (GFP) was virally overexpressed in the EC of adult rats. LFPs were recorded from the dorsal hippocampus and prelimbic medial prefrontal cortex while the rats underwent trace eyeblink conditioning where they learned to associate 2 stimuli separated by a short time interval...
July 6, 2017: Neurobiology of Aging
https://www.readbyqxmd.com/read/28713841/design-and-implementation-of-an-optimal-laser-pulse-front-tilting-scheme-for-ultrafast-electron-diffraction-in-reflection-geometry-with-high-temporal-resolution
#7
Francesco Pennacchio, Giovanni M Vanacore, Giulia F Mancini, Malte Oppermann, Rajeswari Jayaraman, Pietro Musumeci, Peter Baum, Fabrizio Carbone
Ultrafast electron diffraction is a powerful technique to investigate out-of-equilibrium atomic dynamics in solids with high temporal resolution. When diffraction is performed in reflection geometry, the main limitation is the mismatch in group velocity between the overlapping pump light and the electron probe pulses, which affects the overall temporal resolution of the experiment. A solution already available in the literature involved pulse front tilt of the pump beam at the sample, providing a sub-picosecond time resolution...
July 2017: Structural Dynamics (Melville, N.Y.)
https://www.readbyqxmd.com/read/28713250/impaired-in-vivo-gamma-oscillations-in-the-medial-entorhinal-cortex-of-knock-in-alzheimer-model
#8
Tomoaki Nakazono, Travis N Lam, Ayushi Y Patel, Masashi Kitazawa, Takashi Saito, Takaomi C Saido, Kei M Igarashi
The entorhinal cortex (EC) has bidirectional connections with the hippocampus and plays a critical role in memory formation and retrieval. EC is one of the most vulnerable regions in the brain in early stages of Alzheimer's disease (AD), a neurodegenerative disease with progressive memory impairments. Accumulating evidence from healthy behaving animals indicates gamma oscillations (30-100 Hz) as critical for mediating interactions in the circuit between EC and hippocampus. However, it is still unclear whether gamma oscillations have causal relationship with memory impairment in AD...
2017: Frontiers in Systems Neuroscience
https://www.readbyqxmd.com/read/28696761/parametric-oscillation-frequency-mixing-and-injection-locking-of-strongly-coupled-nanomechanical-resonator-modes
#9
Maximilian J Seitner, Mehdi Abdi, Alessandro Ridolfo, Michael J Hartmann, Eva M Weig
We study locking phenomena of two strongly coupled, high quality factor nanomechanical resonator modes to a common parametric drive at a single drive frequency in different parametric driving regimes. By controlled dielectric gradient forces we tune the resonance frequencies of the flexural in-plane and out-of-plane oscillation of the high stress silicon nitride string through their mutual avoided crossing. For the case of the strong common parametric drive signal-idler generation via nondegenerate parametric two-mode oscillation is observed...
June 23, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28670431/evaluation-on-hope-and-psychological-symptoms-in-infertile-couples-undergoing-assisted-reproduction-treatment
#10
Reza Omani Samani, Samira Vesali, Behnaz Navid, Bahareh Vakiliniya, Maryam Mohammadi
BACKGROUND: This study evaluated hope, depression, anxiety, and stress among three groups of infertile couples. MATERIALS AND METHODS: This cross-sectional study consisted of three groups of infertile couples-candidates for oocyte donation (n=60), embryo donation (n=60), and normal infertile (n=60). Participants included couples seen at Royan Institute, Tehran, Iran between 2013-2014 who were at least 18 years of age and could read and write in Persian. Participants provided demographic and general characteristics and completed the Persian version of the Adult Trait Hope Scale (hope, agency and pathway) and Depression, Anxiety, and Stress Scale (DASS)...
July 2017: International Journal of Fertility & Sterility
https://www.readbyqxmd.com/read/28668059/planarizing-cytosine-the-s1-state-structure-vibrations-and-nonradiative-dynamics-of-jet-cooled-5-6-trimethylenecytosine
#11
Maria A Trachsel, Simon Lobsiger, Tobias Schär, Lluís Blancafort, Samuel Leutwyler
We measure the S0 → S1 spectrum and time-resolved S1 state nonradiative dynamics of the "clamped" cytosine derivative 5,6-trimethylenecytosine (TMCyt) in a supersonic jet, using two-color resonant two-photon ionization (R2PI), UV/UV holeburning, and ns time-resolved pump/delayed ionization. The experiments are complemented with spin-component scaled second-order approximate coupled cluster (SCS-CC2), time-dependent density functional theory, and multi-state second-order perturbation-theory (MS-CASPT2) ab initio calculations...
June 28, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28668050/ionization-of-pyridine-interplay-of-orbital-relaxation-and-electron-correlation
#12
A B Trofimov, D M P Holland, I Powis, R C Menzies, A W Potts, L Karlsson, E V Gromov, I L Badsyuk, J Schirmer
The valence shell ionization spectrum of pyridine was studied using the third-order algebraic-diagrammatic construction approximation scheme for the one-particle Green's function and the outer-valence Green's function method. The results were used to interpret angle resolved photoelectron spectra recorded with synchrotron radiation in the photon energy range of 17-120 eV. The lowest four states of the pyridine radical cation, namely, (2)A2(1a2(-1)), (2)A1(7a1(-1)), (2)B1(2b1(-1)), and (2)B2(5b2(-1)), were studied in detail using various high-level electronic structure calculation methods...
June 28, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28663726/neural-cross-frequency-coupling-functions
#13
Tomislav Stankovski, Valentina Ticcinelli, Peter V E McClintock, Aneta Stefanovska
Although neural interactions are usually characterized only by their coupling strength and directionality, there is often a need to go beyond this by establishing the functional mechanisms of the interaction. We introduce the use of dynamical Bayesian inference for estimation of the coupling functions of neural oscillations in the presence of noise. By grouping the partial functional contributions, the coupling is decomposed into its functional components and its most important characteristics-strength and form-are quantified...
2017: Frontiers in Systems Neuroscience
https://www.readbyqxmd.com/read/28662486/sensitivity-enhancement-by-multiple-contact-cross-polarization-under-magic-angle-spinning
#14
J Raya, J Hirschinger
Multiple-contact cross-polarization (MC-CP) is applied to powder samples of ferrocene and l-alanine under magic-angle spinning (MAS) conditions. The method is described analytically through the density matrix formalism. The combination of a two-step memory function approach and the Anderson-Weiss approximation is found to be particularly useful to derive approximate analytical solutions for single-contact Hartmann-Hahn CP (HHCP) and MC-CP dynamics under MAS. We show that the MC-CP sequence requiring no pulse-shape optimization yields higher polarizations at short contact times than optimized adiabatic passage through the HH condition CP (APHH-CP) when the MAS frequency is comparable to the heteronuclear dipolar coupling, i...
June 16, 2017: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/28659769/propofol-sevoflurane-and-ketamine-induce-a-reversible-increase-in-delta-gamma-and-theta-gamma-phase-amplitude-coupling-in-frontal-cortex-of-rat
#15
Dinesh Pal, Brian H Silverstein, Lana Sharba, Duan Li, Viviane S Hambrecht-Wiedbusch, Anthony G Hudetz, George A Mashour
Studies from human and non-human species have demonstrated a breakdown of functional corticocortical connectivity during general anesthesia induced by anesthetics with diverse molecular, neurophysiological, and pharmacological profiles. Recent studies have demonstrated that changes in long-range neural communication, and by corollary, functional connectivity, might be influenced by cross-frequency coupling (CFC) between the phase of slow oscillations and the amplitude of local fast oscillations. Phase-amplitude coupling (PAC) between slow oscillations and alpha rhythm during general anesthesia reveal distinct patterns depending on the anesthetic...
2017: Frontiers in Systems Neuroscience
https://www.readbyqxmd.com/read/28656925/family-planning-practices-of-rural-community-dwellers-in-cross-river-state-nigeria
#16
A J Etokidem, W Ndifon, J Etowa, E F Asuquo
BACKGROUND: Nigeria is the most populous nation in Africa and the seventh most populous in the world. Despite a high fertility rate of 5.5 per woman and a high population growth rate of 3.2%, Nigeria's contraceptive prevalence is 15%, which is one of the lowest in the world. The objective of this study was to determine the knowledge of family planning and family planning preferences and practices of rural community women in Cross River State of Nigeria. MATERIALS AND METHODS: This was a cross-sectional study involving 291 rural women...
June 2017: Nigerian Journal of Clinical Practice
https://www.readbyqxmd.com/read/28647431/temporal-segmentation-for-laryngeal-high-speed-videoendoscopy-in-connected-speech
#17
Maryam Naghibolhosseini, Dimitar D Deliyski, Stephanie R C Zacharias, Alessandro de Alarcon, Robert F Orlikoff
OBJECTIVE: This study proposes a gradient-based method for temporal segmentation of laryngeal high-speed videoendoscopy (HSV) data obtained during connected speech. METHODS: A custom-developed HSV system coupled with a flexible fiberoptic nasolaryngoscope was used to record one vocally normal female participant during reading of the "Rainbow Passage." A gradient-based algorithm was developed to generate a motion window. When applied to the HSV data, the motion window acted as a filter tracking the location of the vibrating vocal folds...
June 21, 2017: Journal of Voice: Official Journal of the Voice Foundation
https://www.readbyqxmd.com/read/28637840/promoting-sleep-oscillations-and-their-functional-coupling-by-transcranial-stimulation-enhances-memory-consolidation-in-mild-cognitive-impairment
#18
Julia Ladenbauer, Josef Ladenbauer, Nadine Külzow, Rebecca de Boor, Elena Avramova, Ulrike Grittner, Agnes Flöel
Alzheimer's disease (AD) not only involves loss of memory functions, but also prominent deterioration of sleep physiology, which is already evident at the stage of mild cognitive impairment (MCI). Cortical slow oscillations (SO; 0.5-1 Hz) and thalamocortical spindle activity (12-15 Hz) during sleep, and their temporal coordination, are considered critical for memory formation. We investigated the potential of slow oscillatory transcranial direct current stimulation (so-tDCS), applied during a daytime nap in a sleep-state-dependent manner, to modulate these activity patterns and sleep-related memory consolidation in nine male and seven female human patients with MCI...
July 26, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28621583/effect-of-a-publicly-accessible-disclosure-system-on-food-safety-inspection-scores-in-retail-and-food-service-establishments
#19
Jihee Choi, Robert L Scharff
The increased frequency with which people are dining out coupled with an increase in the publicity of foodborne disease outbreaks has led the public to an increased awareness of food safety issues associated with food service establishments. To accommodate consumer needs, local health departments have increasingly publicized food establishments' health inspection scores. The objective of this study was to estimate the effect of the color-coded inspection score disclosure system in place since 2006 in Columbus, OH, by controlling for several confounding factors...
June 16, 2017: Journal of Food Protection
https://www.readbyqxmd.com/read/28618492/spontaneous-exchange-of-leader-laggard-relationship-in-mutually-coupled-synchronized-semiconductor-lasers
#20
Kazutaka Kanno, Takuya Hida, Atsushi Uchida, Masatoshi Bunsen
We investigate the instantaneous behavior of synchronized temporal wave forms in two mutually coupled semiconductor lasers numerically and experimentally. The temporal wave forms of two lasers are synchronized with a propagation delay time, with one laser oscillating in advance of the other, known as the leader-laggard relationship. The leader-laggard relationship can be determined by measuring the cross-correlation between the two temporal wave forms with the propagation delay time. The leader can be identified when the optical carrier frequency of the leader laser is higher than that of the other laser...
May 2017: Physical Review. E
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