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https://www.readbyqxmd.com/read/28087654/effects-of-external-strain-on-the-regulation-of-microtubule-sliding-induced-by-outer-arm-dynein-of-sea-urchin-sperm-flagella
#1
Hiroshi Yoke, Chikako Shingyoji
Oscillatory bending movement of eukaryotic flagella is powered by orchestrated activity of dynein motor proteins that hydrolyze ATP and produce microtubule sliding. Although the ATP concentration within a flagellum is kept uniform at a few mmol l(-1) level, sliding activities of dyneins are dynamically coordinated along the flagellum in accordance with the phase of bending waves. Thus, at the organellar level the dynein not only generates force for bending but also modulates its motile activity by responding to bending of the flagellum...
January 13, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/28078839/widespread-membrane-potential-changes-and-cardiorespiratory-synchronization-involved-in-anxiety-and-sleep-wake-transitions
#2
R Jerath, S M Cearley, M Jensen
Located within the ascending reticular activating system are nuclei which release neurotransmitters such as acetylcholine, serotonin, dopamine, and norepinephrine. These nuclei have widespread projections that extend into the limbic system and throughout cortex. Activation of these neurotransmitters during awake states leads to arousal, while inhibition leads to the loss of consciousness experienced during slow-wave sleep. Previously, we proposed a mechanism in which cardiorespiratory synchronization may underlie the widespread hyperpolarization that occurs throughout the brain during slow-wave sleep...
October 2016: Journal of Biological Regulators and Homeostatic Agents
https://www.readbyqxmd.com/read/28077278/oscillatory-eeg-activity-induced-by-conditioning-stimuli-during-fear-conditioning-reflects-salience-and-valence-of-these-stimuli-more-than-expectancy
#3
J H Chien, L Colloca, A Korzeniewska, J J Cheng, C M Campbell, A E Hillis, F A Lenz
Imaging studies have described hemodynamic activity during fear conditioning protocols with stimulus trains in which a visual conditioned stimulus (CS+) is paired with an aversive unconditioned stimulus (US, painful laser pulse) while another visual stimulus is unpaired (CS-). We now test the hypothesis that CS Event Related Spectral Perturbations (ERSPs) are related to ratings of CS Expectancy (likelihood of pairing with the US), Valence (unpleasantness) and Salience (ability to capture attention). ERSP windows in EEG were defined by both time after the CS and frequency, and showed increased oscillatory power (Event Related Synchronization, ERS) in the delta/theta Windows (0-8 Hz) and the gamma Window (30-55 Hz)...
January 7, 2017: Neuroscience
https://www.readbyqxmd.com/read/28077003/influence-of-extrinsic-inputs-and-synaptic-gains-on-dynamics-of-wendling-s-neural-mass-model-a-bifurcation-analysis
#4
Shujuan Geng, Weidong Zhou
We analyze the neurodynamics attributed by a model proposed by Wendling and co-workers (2002) [Wendling, F., Bartolomei, F., Bellanger, J.J. & Chauvel, P. (2002) Epileptic fast activity can be explained by a model of impaired GABAergic dendritic inhibition. Eur. J. Neurosci., 15, 1499.] to explain several different types of electroencephalographic activities. We could find three principal types of steady states when the system parameters change slowly: (i) the model produce a constant output when it is under a state of stable equilibrium point with a constant input...
January 11, 2017: Journal of Integrative Neuroscience
https://www.readbyqxmd.com/read/28076567/full-field-electroretinogram-recorded-with-skin-electrodes-in-normal-adults
#5
Arthur Gustavo Fernandes, Solange Rios Salomão, Josenilson Martins Pereira, Adriana Berezovsky
Purpose: Alternative recording methods have been tested to allow the electroretinogram (ERG) recording in uncooperative patients and/or patients with palpebral alterations, including recordings with skin electrodes. The purpose of this study was to compare ERG recorded with skin electrodes and well-established microfiber electrodes and to determine normative values of ERG parameters for recording with skin electrodes. Methods: Fifty healthy volunteers (17-26 years; mean 20...
November 2016: Arquivos Brasileiros de Oftalmologia
https://www.readbyqxmd.com/read/28076421/oscillatory-dynamics-supporting-semantic-cognition-meg-evidence-for-the-contribution-of-the-anterior-temporal-lobe-hub-and-modality-specific-spokes
#6
Giovanna Mollo, Piers L Cornelissen, Rebecca E Millman, Andrew W Ellis, Elizabeth Jefferies
The "hub and spoke model" of semantic representation suggests that the multimodal features of objects are drawn together by an anterior temporal lobe (ATL) "hub", while modality-specific "spokes" capture perceptual/action features. However, relatively little is known about how these components are recruited through time to support object identification. We used magnetoencephalography to measure neural oscillations within left ATL, lateral fusiform cortex (FC) and central sulcus (CS) during word-picture matching at different levels of specificity (employing superordinate vs...
2017: PloS One
https://www.readbyqxmd.com/read/28076347/spatiotemporal-feedback-and-network-structure-drive-and-encode-caenorhabditis-elegans-locomotion
#7
James M Kunert, Joshua L Proctor, Steven L Brunton, J Nathan Kutz
Using a computational model of the Caenorhabditis elegans connectome dynamics, we show that proprioceptive feedback is necessary for sustained dynamic responses to external input. This is consistent with the lack of biophysical evidence for a central pattern generator, and recent experimental evidence that proprioception drives locomotion. The low-dimensional functional response of the Caenorhabditis elegans network of neurons to proprioception-like feedback is optimized by input of specific spatial wavelengths which correspond to the spatial scale of real body shape dynamics...
January 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28075334/spin-and-valley-dependent-electron-transport-through-arrays-of-ferromagnet-on-monolayer-mos-sub-2-sub
#8
Xue-Jun Qiu, Zhen-Zhou Cao, Yan-Fu Cheng, Chaochao Qin
We theoretically study ballistic transport of Dirac fermions in MoS<sub>2</sub> junction through arrays of barriers, of width L , in the presence of a tunable potential of height U and an exchange field h .The charge conductance as functions of U and h , exhibits more conspicuous and sharpened oscillation as the number of barriers increase, due to the contribution of evanescent modes near the edges of the extremum conductance which are exponentially suppressed or enhanced. Furthermore, we found the valley-resolved conductance exhibits a similar oscillating behavior as the charge conductance for multiple barriers, but with inverse oscillatory phases for G<sub>K</sub> and G<sub>K'</sub>, accordingly, a high-efficiency fully valley polarized device is proposed in our system...
January 11, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/28074926/disrupted-global-metastability-and-static-and-dynamic-brain-connectivity-across-individuals-in-the-alzheimer-s-disease-continuum
#9
Aldo Córdova-Palomera, Tobias Kaufmann, Karin Persson, Dag Alnæs, Nhat Trung Doan, Torgeir Moberget, Martina Jonette Lund, Maria Lage Barca, Andreas Engvig, Anne Brækhus, Knut Engedal, Ole A Andreassen, Geir Selbæk, Lars T Westlye
As findings on the neuropathological and behavioral components of Alzheimer's disease (AD) continue to accrue, converging evidence suggests that macroscale brain functional disruptions may mediate their association. Recent developments on theoretical neuroscience indicate that instantaneous patterns of brain connectivity and metastability may be a key mechanism in neural communication underlying cognitive performance. However, the potential significance of these patterns across the AD spectrum remains virtually unexplored...
January 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28071688/epileptiform-activity-in-the-mouse-visual-cortex-interferes-with-cortical-processing-in-connected-areas
#10
L Petrucco, E Pracucci, M Brondi, G M Ratto, S Landi
Epileptiform activity is associated with impairment of brain function even in absence of seizures, as demonstrated by failures in various testing paradigm in presence of hypersynchronous interictal spikes (ISs). Clinical evidence suggests that cognitive deficits might be directly caused by the anomalous activity rather than by its underlying etiology. Indeed, we seek to understand whether ISs interfere with neuronal processing in connected areas not directly participating in the hypersynchronous activity in an acute model of epilepsy...
January 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28070124/an-endophenotype-approach-to-the-genetics-of-alcohol-dependence-a-genome-wide-association-study-of-fast-beta-eeg-in-families-of-african-ancestry
#11
J L Meyers, J Zhang, J C Wang, J Su, S I Kuo, M Kapoor, L Wetherill, S Bertelsen, D Lai, J E Salvatore, C Kamarajan, D Chorlian, A Agrawal, L Almasy, L Bauer, K K Bucholz, G Chan, V Hesselbrock, L Koganti, J Kramer, S Kuperman, N Manz, A Pandey, M Seay, D Scott, R E Taylor, D M Dick, H J Edenberg, A Goate, T Foroud, B Porjesz
Fast beta (20-28 Hz) electroencephalogram (EEG) oscillatory activity may be a useful endophenotype for studying the genetics of disorders characterized by neural hyperexcitability, including substance use disorders (SUDs). However, the genetic underpinnings of fast beta EEG have not previously been studied in a population of African-American ancestry (AA). In a sample of 2382 AA individuals from 482 families drawn from the Collaborative Study on the Genetics of Alcoholism (COGA), we performed a genome-wide association study (GWAS) on resting-state fast beta EEG power...
January 10, 2017: Molecular Psychiatry
https://www.readbyqxmd.com/read/28069165/on-the-quantification-and-visualization-of-transient-periodic-instabilities-in-pulsatile-flows
#12
Muhammad Owais Khan, Christophe Chnafa, Diego Gallo, Filippo Molinari, Umberto Morbiducci, David A Steinman, Kristian Valen-Sendstad
Turbulent-like flows without cycle-to-cycle variations are more frequently being reported in studies of cardiovascular flows. The associated stimuli might be of mechanobiological relevance, but how to quantify them objectively is not obvious. Classical Reynolds decomposition, where the flow is separated into mean and fluctuating velocity components, is not applicable as the phase-average is zero. We therefore expanded on established techniques and present the idea, analogous to Reynolds decomposition, to decompose a flow with transient instabilities into low- versus high frequency components, respectively, to discriminate flow instabilities from the underlying cardiac pulsatility...
December 31, 2016: Journal of Biomechanics
https://www.readbyqxmd.com/read/28068428/a-network-model-of-local-field-potential-activity-in-essential-tremor-and-the-impact-of-deep-brain-stimulation
#13
Nada Yousif, Michael Mace, Nicola Pavese, Roman Borisyuk, Dipankar Nandi, Peter Bain
Essential tremor (ET), a movement disorder characterised by an uncontrollable shaking of the affected body part, is often professed to be the most common movement disorder, affecting up to one percent of adults over 40 years of age. The precise cause of ET is unknown, however pathological oscillations of a network of a number of brain regions are implicated in leading to the disorder. Deep brain stimulation (DBS) is a clinical therapy used to alleviate the symptoms of a number of movement disorders. DBS involves the surgical implantation of electrodes into specific nuclei in the brain...
January 9, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28063666/development-of-a-clinical-applicable-graphical-user-interface-to-automatically-detect-exercise-oscillatory-ventilation-the-vodex-tool
#14
Justien Cornelis, Tim Denis, Paul Beckers, Christiaan Vrints, Dirk Vissers, Maggy Goossens
BACKGROUND: Cardiopulmonary exercise testing (CPET) gained importance in the prognostic assessment of especially patients with heart failure (HF). A meaningful prognostic parameter for early mortality in HF is exercise oscillatory ventilation (EOV). This abnormal respiratory pattern is recognized by hypo- and hyperventilation during CPET. Up until now, assessment of EOV is mainly done upon visual agreement or manual calculation. The purpose of this research was to automate the interpretation of EOV so this prognostic parameter could be readily investigated during CPET...
December 29, 2016: International Journal of Cardiology
https://www.readbyqxmd.com/read/28059426/the-effect-of-colloidal-aggregates-on-fat-crystal-networks
#15
Raamanand R Chauhan, Roel P A Dullens, Krassimir P Velikov, Dirk G A L Aarts
We investigate the role of a colloidal model system in the crystallization and network formation of lipids. This system consists of fractal fumed silica aggregates. We look at the influence of different solid fat concentrations and fumed silica concentrations on the resulting gel network. Oscillatory rheology shows that the addition of silica to fat-in-oil gels does not significantly affect the magnitude of the storage modulus within the linear viscoelastic region. Interestingly, the range of this region is increased...
January 6, 2017: Food & Function
https://www.readbyqxmd.com/read/28059114/cigarette-smoke-extract-profoundly-suppresses-tnf%C3%AE-mediated-proinflammatory-gene-expression-through-upregulation-of-atf3-in-human-coronary-artery-endothelial-cells
#16
Jack E Teasdale, Georgina G J Hazell, Alasdair M G Peachey, Graciela B Sala-Newby, Charles C T Hindmarch, Tristan R McKay, Mark Bond, Andrew C Newby, Stephen J White
Endothelial dysfunction caused by the combined action of disturbed flow, inflammatory mediators and oxidants derived from cigarette smoke is known to promote coronary atherosclerosis and increase the likelihood of myocardial infarctions and strokes. Conversely, laminar flow protects against endothelial dysfunction, at least in the initial phases of atherogenesis. We studied the effects of TNFα and cigarette smoke extract on human coronary artery endothelial cells under oscillatory, normal laminar and elevated laminar shear stress for a period of 72 hours...
January 6, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28058437/sorting-ring-polymers-by-knot-type-with-modulated-nanochannels
#17
Mattia Marenda, Enzo Orlandini, Cristian Micheletti
In this theoretical study we discuss a novel method for sorting ring polymers according to their topological, knotted state. The proposed approach harnesses the rich dynamical behaviour of polymers confined inside spatially-modulated nanochannels. The longitudinal mobility of the rings is shown to have two key properties that are ideally suited for knot sorting. First, at fixed topology, the mobility has an intriguing oscillatory dependence on chain length. Second, the mobility ranking of different knot types is inverted upon increasing the chain length...
January 6, 2017: Soft Matter
https://www.readbyqxmd.com/read/28057457/sustainable-theory-of-a-logistic-model-fisher-information-approach
#18
Avan Al-Saffar, Eun-Jin Kim
Information theory provides a useful tool to understand the evolution of complex nonlinear systems and their sustainability. In particular, Fisher information has been evoked as a useful measure of sustainability and the variability of dynamical systems including self-organising systems. By utilising Fisher information, we investigate the sustainability of the logistic model for different perturbations in the positive and/or negative feedback. Specifically, we consider different oscillatory modulations in the parameters for positive and negative feedback and investigate their effect on the evolution of the system and Probability Density Functions (PDFs)...
January 2, 2017: Mathematical Biosciences
https://www.readbyqxmd.com/read/28053151/optimized-temporal-pattern-of-brain-stimulation-designed-by-computational-evolution
#19
David T Brocker, Brandon D Swan, Rosa Q So, Dennis A Turner, Robert E Gross, Warren M Grill
Brain stimulation is a promising therapy for several neurological disorders, including Parkinson's disease. Stimulation parameters are selected empirically and are limited to the frequency and intensity of stimulation. We varied the temporal pattern of deep brain stimulation to ameliorate symptoms in a parkinsonian animal model and in humans with Parkinson's disease. We used model-based computational evolution to optimize the stimulation pattern. The optimized pattern produced symptom relief comparable to that from standard high-frequency stimulation (a constant rate of 130 or 185 Hz) and outperformed frequency-matched standard stimulation in a parkinsonian rat model and in patients...
January 4, 2017: Science Translational Medicine
https://www.readbyqxmd.com/read/28053032/a-spiking-working-memory-model-based-on-hebbian-short-term-potentiation
#20
Florian Fiebig, Anders Lansner
: A dominant theory of working memory (WM), referred to as the persistent activity hypothesis, holds that recurrently connected neural networks, presumably located in the prefrontal cortex, encode and maintain WM memory items through sustained elevated activity. Reexamination of experimental data has shown that prefrontal cortex activity in single units during delay periods is much more variable than predicted by such a theory and associated computational models. Alternative models of WM maintenance based on synaptic plasticity, such as short-term nonassociative (non-Hebbian) synaptic facilitation, have been suggested but cannot account for encoding of novel associations...
January 4, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
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