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https://www.readbyqxmd.com/read/27915366/aging-has-the-opposite-effect-on-camp-and-cgmp-circadian-variations-in-rat-leydig-cells
#1
Aleksandar Z Baburski, Srdjan J Sokanovic, Silvana A Andric, Tatjana S Kostic
The Leydig cell physiology displays a circadian rhythm driven by a complex interaction of the reproductive axis hormones and circadian system. The final output of this regulatory process is circadian pattern of steroidogenic genes expression and testosterone production. Aging gradually decreases robustness of rhythmic testosterone secretion without change in pattern of LH secretion. Here, we analyzed effect of aging on circadian variation of cAMP and cGMP signaling in Leydig cells. Results showed opposite effect of aging on cAMP and cGMP daily variation...
December 3, 2016: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/27915136/dynamics-of-two-interacting-bubbles-in-a-nonspherical-ultrasound-field
#2
Jinfu Liang, Xun Wang, Jing Yang, Lunxun Gong
In this paper, we present and analyze a model of the oscillations of a pair of gas bubbles driven by nonspherical ultrasound. We derived our model based on the perturbation and potential flow theories and use it to study three cases of oscillation of two bubbles under driving ultrasound with different initial phases, different separation distances between the bubbles and different sound pressure amplitudes. For the driving ultrasound with different initial phases, we obtain the in-phase and anti-phase radial pulsations of the bubbles in incompressible liquid...
November 22, 2016: Ultrasonics
https://www.readbyqxmd.com/read/27915117/from-intentions-to-actions-neural-oscillations-encode-motor-processes-through-phase-amplitude-and-phase-amplitude-coupling
#3
Etienne Combrisson, Marcela Perrone-Bertolotti, Juan Lp Soto, Golnoush Alamian, Philippe Kahane, Jean-Philippe Lachaux, Aymeric Guillot, Karim Jerbi
Goal-directed motor behavior is associated with changes in patterns of rhythmic neuronal activity across widely distributed brain areas. In particular, movement initiation and execution are mediated by patterns of synchronization and desynchronization that occur concurrently across distinct frequency bands and across multiple motor cortical areas. To date, motor-related local oscillatory modulations have been predominantly examined by quantifying increases or suppressions in spectral power. However, beyond signal power, spectral properties such as phase and phase-amplitude coupling (PAC) have also been shown to carry information with regards to the oscillatory dynamics underlying motor processes...
November 30, 2016: NeuroImage
https://www.readbyqxmd.com/read/27914929/structured-additive-distributional-regression-for-analyzing-landings-per-unit-effort-in-fisheries-research
#4
Valeria Mamouridis, Nadja Klein, Thomas Kneib, Carmen Cadarso Suarez, Francesc Maynou
We analysed the landings per unit effort (LPUE) from the Barcelona trawl fleet targeting the red shrimp (Aristeus antennatus) using novel Bayesian structured additive distributional regression to gain a better understanding of the dynamics and determinants of variation in LPUE. The data set, covering a time span of 17 years, includes fleet-dependent variables (e.g. the number of trips performed by vessels), temporal variables (inter- and intra-annual variability) and environmental variables (the North Atlantic Oscillation index)...
November 30, 2016: Mathematical Biosciences
https://www.readbyqxmd.com/read/27914448/a-fractional-calculus-model-of-anomalous-dispersion-of-acoustic-waves
#5
Andrew W Wharmby
An empirical formula based on viscoelastic analysis techniques that employs concepts from the fractional calculus that was used to model the dielectric behavior of materials exposed to oscillating electromagnetic fields in the radiofrequency, terahertz, and infrared bands. This work adapts and applies the formula to model viscoelastic behavior of materials that show an apparent increase of phase velocity of vibration with an increase in frequency, otherwise known as anomalous dispersion. A fractional order wave equation is derived through the application of the classic elastic-viscoelastic correspondence principle whose analytical solution is used to describe absorption and dispersion of acoustic waves in the viscoelastic material displaying anomalous dispersion in a specific frequency range...
September 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27914443/converting-sunlight-into-audible-sound-by-means-of-the-photoacoustic-effect-the-heliophone
#6
N B Roozen, C Glorieux, L Liu, M Rychtáriková, T Van der Donck, A Jacobs
One hundred and thirty-five years after Alexander Graham Bell and his assistant Charles Sumner Tainter explored the photoacoustic effect, and about 40 years after Rosencwaig and Gersho modeled the effect in a photoacoustic cell configuration, the phenomenon is revisited in a "Heliophone" device that converts sunlight into sound. The light is focused on a carbon blackened copper coated Kapton foil in an acoustic cell by means of a compound parabolic collimator, and its intensity is modulated by a mechanical chopper...
September 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27914432/simulation-of-nonlinear-propagation-of-biomedical-ultrasound-using-pzflex-and-the-khokhlov-zabolotskaya-kuznetsov-texas-code
#7
Shan Qiao, Edward Jackson, Constantin C Coussios, Robin O Cleveland
Nonlinear acoustics plays an important role in both diagnostic and therapeutic applications of biomedical ultrasound and a number of research and commercial software packages are available. In this manuscript, predictions of two solvers available in a commercial software package, pzflex, one using the finite-element-method (FEM) and the other a pseudo-spectral method, spectralflex, are compared with measurements and the Khokhlov-Zabolotskaya-Kuznetsov (KZK) Texas code (a finite-difference time-domain algorithm)...
September 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27913953/neuroinflammation-induced-downregulation-of-hippocampacal-neuregulin-1-erbb4-signaling-in-the-parvalbumin-interneurons-might-contribute-to-cognitive-impairment-in-a-mouse-model-of-sepsis-associated-encephalopathy
#8
Rong Gao, Mu-Huo Ji, Da-Peng Gao, Run-Hua Yang, Shao-Gang Zhang, Jian-Jun Yang, Jin-Chun Shen
Sepsis-associated encephalopathy (SAE) is a common complication associated with poor prognosis in septic patients, but the underlying mechanism remains unclear. We hypothesized that disturbed neuregulin 1 (NRG1)-ErbB4 signaling in the parvalbumin interneurons was involved in sepsis-induced cognitive impairment in a mouse model of SAE. The SAE model was induced by cecal ligation/perforation (CLP). Animals were randomly divided into the following six groups: sham + vehicle group, sham + NRG1 group, CLP + vehicle group, CLP + NRG1 group, CLP + NRG1 + AG1478 (ErbB4 inhibitor) group, and CLP + minocycline group...
December 2, 2016: Inflammation
https://www.readbyqxmd.com/read/27913791/circadian-transcription-factor-bmal1-regulates-innate-immunity-against-select-rna-viruses
#9
Tanmay Majumdar, Jayeeta Dhar, Sonal Patel, Roman Kondratov, Sailen Barik
BMAL1 (brain and muscle ARNT-like protein 1, also known as MOP3 or ARNT3) belongs to the family of the basic helix-loop-helix (bHLH)-PAS domain-containing transcription factors, and is a key component of the molecular oscillator that generates circadian rhythms. Here, we report that BMAL1-deficient cells are significantly more susceptible to infection by two major respiratory viruses of the Paramyxoviridae family, namely RSV and PIV3. Embryonic fibroblasts from Bmal1(-/-) mice produced nearly 10-fold more progeny virus than their wild type controls...
December 1, 2016: Innate Immunity
https://www.readbyqxmd.com/read/27913591/temporal-expectations-guide-dynamic-prioritization-in-visual-working-memory-through-attenuated-alpha-oscillations
#10
Freek van Ede, Marcel Niklaus, Anna C Nobre
: While working memory is generally considered a highly dynamic mnemonic store, popular laboratory tasks employed to understand its psychological and neural mechanisms (such as change detection and continuous reproduction) often remain relatively "static", involving the retention of a set number of items throughout a shared delay interval. In the current study, we investigated visual working memory in a more dynamic setting, and assessed: 1) whether internally guided temporal expectations can dynamically and reversibly prioritize individual mnemonic items at specific times at which they are deemed most relevant and 2) the neural substrates that support such dynamic prioritization...
December 2, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27913339/a-parametric-study-for-the-design-of-an-optimized-ultrasonic-percussive-planetary-drill-tool
#11
Xuan Li, Patrick Harkness, Kevin Worrall, Ryan Timoney, Margaret Lucas
Traditional rotary drilling for planetary rock sampling, in-situ analysis and sample return, is challenging because the axial force and holding torque requirements are not necessarily compatible with lightweight spacecraft architectures in low-gravity environments. This article seeks to optimize an ultrasonic-percussive drill tool to achieve rock penetration with lower reacted force requirements, with a strategic view towards building an Ultrasonic Planetary Core Drill (UPCD) device. The UPCD is a descendant of the Ultrasonic/Sonic Driller/Corer (USDC) technique...
November 29, 2016: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/27913335/frequency-measurement-system-of-optical-clocks-without-a-flywheel-oscillator
#12
Miho Fujieda, Tetsuya Ido, Hidekazu Hachisu, Tadahiro Gotoh, Hiroshi Takiguchi, Kazuhiro Hayasaka, Kenji Toyoda, Kenji Yonegaki, Utako Tanaka, Shinji Urabe
We developed a system for the remote frequency comparison of optical clocks. The system does not require a flywheel oscillator at the remote end, making it possible to evaluate optical frequencies even in laboratories, where no stable microwave reference, such as an Rb clock, a Cs clock, or a hydrogen maser exists. The system is established by the integration of several systems: a portable carrier-phase two-way satellite frequency transfer station and a microwave signal generation system by an optical frequency comb from an optical clock...
December 2016: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/27913322/automatic-detection-and-classification-of-high-frequency-oscillations-in-depth-eeg-signals
#13
Nisrine Jrad, Amar Kachenoura, Isabelle Merlet, Fabrice Bartolomei, Anca Nica, Arnaud Biraben, Fabrice Wendling
GOAL: Interictal High Frequency Oscillations (HFOs [30-600 Hz]) have proven to be relevant biomarkers in epilepsy. In this paper, four categories of HFOs are considered: Gamma ([30- 80 Hz]), High-Gamma ([80-120 Hz]), Ripples ([120-250 Hz]) and Fast-Ripples ([250-600 Hz]). A universal detector of the four types of HFOs is proposed. It has the advantages of i) classifying HFOs, and thus being robust to inter- and intra-subject variability; ii) rejecting artefacts, thus being specific. METHODS: Gabor atoms are tuned to cover the physiological bands...
November 29, 2016: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/27913167/gamma-band-directional-interactions-between-basal-forebrain-and-visual-cortex-during-wake-and-sleep-states
#14
Jayakrishnan Nair, Arndt-Lukas Klaassen, Jordan Poirot, Alexei Vyssotski, Björn Rasch, Gregor Rainer
The basal forebrain (BF) is an important regulator of cortical excitability and responsivity to sensory stimuli, and plays a major role in wake-sleep regulation. While the impact of BF on cortical EEG or LFP signals has been extensively documented, surprisingly little is known about LFP activity within BF. Based on bilateral recordings from rats in their home cage, we describe endogenous LFP oscillations in the BF during quiet wakefulness, rapid eye movement (REM) and slow wave sleep (SWS) states. Using coherence and Granger causality methods, we characterize directional influences between BF and visual cortex (VC) during each of these states...
November 29, 2016: Journal of Physiology, Paris
https://www.readbyqxmd.com/read/27912850/oscillating-in-and-out-of-place-experiences-of-older-adults-residing-in-homeless-shelters-in-montreal-quebec
#15
Victoria F Burns
Aging in place is desirable from the perspective of older adults and policy makers alike. However, the meaning of 'place' for adults experiencing homelessness has been largely overlooked. Addressing this gap, this constructivist grounded theory study discusses the meaning of place for 15 older adults residing in emergency homeless shelters in Montreal, Quebec. Findings revealed that four interrelated dimensions of place-that is, control, comfort, privacy, and security were instrumental in supporting participants' ability to feel in place across housed-homeless trajectories...
December 2016: Journal of Aging Studies
https://www.readbyqxmd.com/read/27912172/brain-heart-communication-evidence-for-central-pacemaker-oscillations-with-a-dominant-frequency-at-0-1hz-in-the-cingulum
#16
Gert Pfurtscheller, Andreas R Schwerdtfeger, Annemarie Seither-Preisler, Clemens Brunner, Christoph Stefan Aigner, Joana Brito, Marciano P Carmo, Alexandre Andrade
OBJECTIVES: In the brain and heart, oscillations at about 0.1Hz are conspicuous. It is therefore worthwhile to study the interaction between intrinsic BOLD oscillations (0.1Hz) and slow oscillations in heart rate interval (RRI) signals and differentiate between their neural and vascular origin. METHODS: We studied the phase-coupling with a 3T scanner with high scanning rate between BOLD signals in 22 regions and simultaneously recorded RRI oscillations in 23 individuals in two resting states...
November 10, 2016: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/27912169/non-harmonicity-in-high-frequency-components-of-the-intra-operative-corticogram-to-delineate-epileptogenic-tissue-during-surgery
#17
Evelien E Geertsema, Maryse A van 't Klooster, Nicole E C van Klink, Frans S S Leijten, Peter C van Rijen, Gerhard H Visser, Stiliyan N Kalitzin, Maeike Zijlmans
OBJECTIVE: We aimed to test the potential of auto-regressive model residual modulation (ARRm), an artefact-insensitive method based on non-harmonicity of the high-frequency signal, to identify epileptogenic tissue during surgery. METHODS: Intra-operative electrocorticography (ECoG) of 54 patients with refractory focal epilepsy were recorded pre- and post-resection at 2048Hz. The ARRm was calculated in one-minute epochs in which high-frequency oscillations (HFOs; fast ripples, 250-500Hz; ripples, 80-250Hz) and spikes were marked...
November 17, 2016: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/27912128/time-to-grow-circadian-regulation-of-growth-and-metabolism-in-photosynthetic-organisms
#18
REVIEW
Santiago Mora-García, María José de Leone, Marcelo Yanovsky
Circadian clocks are molecular devices that help adjust organisms to periodic environmental changes. Although formally described as self-sustaining oscillators that are synchronized by external cues and produce defined outputs, it is increasingly clear that physiological processes not only are regulated by, but also regulate the function of the clock. We discuss three recent examples of the intimate relationships between the function of the clock, growth and metabolism in photosynthetic organisms: the daily tracking of sun by sunflowers, the fine computations plants and cyanobacteria perform to manage carbon reserves and prevent starvation, and the changes in clock parameters that went along with domestication of tomato...
November 29, 2016: Current Opinion in Plant Biology
https://www.readbyqxmd.com/read/27912066/cell-type-specific-optical-recording-of-membrane-voltage-dynamics-in-freely-moving-mice
#19
Jesse D Marshall, Jin Zhong Li, Yanping Zhang, Yiyang Gong, François St-Pierre, Michael Z Lin, Mark J Schnitzer
Electrophysiological field potential dynamics are of fundamental interest in basic and clinical neuroscience, but how specific cell types shape these dynamics in the live brain is poorly understood. To empower mechanistic studies, we created an optical technique, TEMPO, that records the aggregate trans-membrane voltage dynamics of genetically specified neurons in freely behaving mice. TEMPO has >10-fold greater sensitivity than prior fiber-optic techniques and attains the noise minimum set by quantum mechanical photon shot noise...
December 1, 2016: Cell
https://www.readbyqxmd.com/read/27912059/microbiota-diurnal-rhythmicity-programs-host-transcriptome-oscillations
#20
Christoph A Thaiss, Maayan Levy, Tal Korem, Lenka Dohnalová, Hagit Shapiro, Diego A Jaitin, Eyal David, Deborah R Winter, Meital Gury-BenAri, Evgeny Tatirovsky, Timur Tuganbaev, Sara Federici, Niv Zmora, David Zeevi, Mally Dori-Bachash, Meirav Pevsner-Fischer, Elena Kartvelishvily, Alexander Brandis, Alon Harmelin, Oren Shibolet, Zamir Halpern, Kenya Honda, Ido Amit, Eran Segal, Eran Elinav
The intestinal microbiota undergoes diurnal compositional and functional oscillations that affect metabolic homeostasis, but the mechanisms by which the rhythmic microbiota influences host circadian activity remain elusive. Using integrated multi-omics and imaging approaches, we demonstrate that the gut microbiota features oscillating biogeographical localization and metabolome patterns that determine the rhythmic exposure of the intestinal epithelium to different bacterial species and their metabolites over the course of a day...
December 1, 2016: Cell
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