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Konstantina Kalogianni, Andreas Daffertshofer, Frans C T van der Helm, Alfred C Schouten, Jan C de Munck
In searching for clinical biomarkers of the somatosensory function, we studied reproducibility of somatosensory potentials (SEP) evoked by finger stimulation in healthy subjects. SEPs induced by electrical stimulation and especially after median nerve stimulation is a method widely used in the literature. It is unclear, however, if the EEG recordings after finger stimulation are reproducible within the same subject. We tested in five healthy subjects the consistency and reproducibility of responses through bootstrapping as well as test-retest recordings...
January 20, 2018: Brain Topography
Ian Grasso, Mark Haigney, David Mortara, Jacob F Collen, Jordanna Hostler, Aimee Moores, Karen Sheikh, William Kelly
PURPOSE: Obstructive sleep apnea (OSA) syndrome is a common condition that can impact clinical outcomes among patients with cardiovascular disease. Screening all subjects with heart disease via polysomnography (PSG) is costly and resource-limited. We sought to compare a Holter monitor-based algorithm to detect OSA to in-laboratory polysomnography (PSG). METHODS: Prospective cohort study of patients undergoing in-laboratory attended PSG for the evaluation of OSA...
January 20, 2018: Sleep & Breathing, Schlaf & Atmung
Fares A Almomani, Banu Örmeci
Monitoring of microalgae in water supplies and industrial applications are becoming increasingly important, yet there are few options available that are simple and accurate, and can provide real-time information. The present work illustrates a new method to determine the concentration of microalgae in water and wastewater using spectrophotometry and the first derivative of absorbance. Chlorella vulgaris was used as an indicator microalga, spiked in water samples representing a range of water qualities (distilled water, surface water, and wastewater), and correlations among C...
January 20, 2018: Environmental Monitoring and Assessment
Stefano Grigolato, Omar Mologni, Andrea Rosario Proto, Giuseppe Zimbalatti, Raffaele Cavalli
The use of helicopter rises discussion about environmental noise propagation especially when it operates in proximity of environmentally sensitive areas (ESAs) for an extended period because of its potential implications in wildlife behaviours. In order to support decisions on helicopter logging operation management in proximity of ESAs, this study focused on (i) analysing the noise spectrum of a light-lift helicopter during logging operations and on (ii) assessing the noise propagation in the surrounding environments...
January 20, 2018: Environmental Monitoring and Assessment
Vivian Holten, Paul R MacNeilage
Optic flow patterns generated by self-motion relative to the stationary environment result in congruent visual-vestibular self-motion signals. Incongruent signals can arise due to object motion, vestibular dysfunction, or artificial stimulation, which are less common. Hence, we are predominantly exposed to congruent rather than incongruent visual-vestibular stimulation. If the brain takes advantage of this probabilistic association, we expect observers to be more sensitive to visual optic flow that is congruent with ongoing vestibular stimulation...
2018: PloS One
Seong Jun Park, Sanggeun Song, Gil-Suk Yang, Philip M Kim, Sangwoon Yoon, Ji-Hyun Kim, Jaeyoung Sung
Gene expression is a complex stochastic process composed of numerous enzymatic reactions with rates coupled to hidden cell-state variables. Despite advances in single-cell technologies, the lack of a theory accurately describing the gene expression process has restricted a robust, quantitative understanding of gene expression variability among cells. Here we present the Chemical Fluctuation Theorem (CFT), providing an accurate relationship between the environment-coupled chemical dynamics of gene expression and gene expression variability...
January 19, 2018: Nature Communications
Maurizio Righini, Antony Lee, Cristhian Cañari-Chumpitaz, Troy Lionberger, Ronen Gabizon, Yves Coello, Ignacio Tinoco, Carlos Bustamante
In recent years, highly stable optical tweezers systems have enabled the characterization of the dynamics of molecular motors at very high resolution. However, the motion of many motors with angstrom-scale dynamics cannot be consistently resolved due to poor signal-to-noise ratio. Using an acousto-optic deflector to generate a "time-shared" dual-optical trap, we decreased low-frequency noise by more than one order of magnitude compared with conventional dual-trap optical tweezers. Using this instrument, we implemented a protocol that synthesizes single base-pair trajectories, which are used to test a Large State Space Hidden Markov Model algorithm to recover their individual steps...
January 19, 2018: Proceedings of the National Academy of Sciences of the United States of America
W Christopher Carleton, David Campbell, Mark Collard
Statistical time-series analysis has the potential to improve our understanding of human-environment interaction in deep time. However, radiocarbon dating-the most common chronometric technique in archaeological and palaeoenvironmental research-creates challenges for established statistical methods. The methods assume that observations in a time-series are precisely dated, but this assumption is often violated when calibrated radiocarbon dates are used because they usually have highly irregular uncertainties...
2018: PloS One
Sandip Datta, Brian Seed
Experimental data indicate that stochastic effects exerted at the level of translation contribute substantially to the variation in abundance of proteins expressed at moderate to high levels. This study analyzes the theoretical consequences of fluctuations in residue-specific elongation rates during translation. A simple analytical framework shows that rate variation during elongation gives rise to protein production rates that consist of sums of products of random variables. Simulations show that because the contribution to total variation of products of random variables greatly exceeds that of sums of random variables, the overall distribution exhibits approximately log-normal behavior...
2018: PloS One
Jingzhou Xin, Jianting Zhou, Simon X Yang, Xiaoqing Li, Yu Wang
Bridges are an essential part of the ground transportation system. Health monitoring is fundamentally important for the safety and service life of bridges. A large amount of structural information is obtained from various sensors using sensing technology, and the data processing has become a challenging issue. To improve the prediction accuracy of bridge structure deformation based on data mining and to accurately evaluate the time-varying characteristics of bridge structure performance evolution, this paper proposes a new method for bridge structure deformation prediction, which integrates the Kalman filter, autoregressive integrated moving average model (ARIMA), and generalized autoregressive conditional heteroskedasticity (GARCH)...
January 19, 2018: Sensors
Stefan Stevanovic, Boris Pervan
We propose a novel GPS phase-lock loop (PLL) performance metric based on the standard deviation of tracking error (defined as the discriminator's estimate of the true phase error), and explain its advantages over the popular phase jitter metric using theory, numerical simulation, and experimental results. We derive an augmented GPS phase-lock loop (PLL) linear model, which includes the effect of coherent averaging, to be used in conjunction with this proposed metric. The augmented linear model allows more accurate calculation of tracking error standard deviation in the presence of additive white Gaussian noise (AWGN) as compared to traditional linear models...
January 19, 2018: Sensors
Dustin R Osborne, Shelley N Acuff, Melissa L Neveu, Mumtaz Syed, Austin D Kaman, Yitong Fu
PURPOSE: The usage of PET/computed tomography (CT) to monitor hepatocellular carcinoma patients following yttrium-90 (Y) radioembolization has increased. Respiratory motion causes liver movement, which can be corrected using gating techniques at the expense of added noise. This work examines the use of amplitude-based gating on Y-PET/CT and its potential impact on diagnostic integrity. PATIENTS AND METHODS: Patients were imaged using PET/CT following Y radioembolization...
January 18, 2018: Nuclear Medicine Communications
Cătălin Paşcu Moca, Christophe Mora, Ireneusz Weymann, Gergely Zaránd
We construct a Fermi liquid theory to describe transport in a superconductor-quantum dot-normal metal junction close to the singlet-doublet (parity changing) transition of the dot. Though quasiparticles do not have a definite charge in this chargeless Fermi liquid, in the case of particle-hole symmetry, a mapping to the Anderson model unveils a hidden U(1) symmetry and a corresponding pseudocharge. In contrast to other correlated Fermi liquids, the back scattering noise reveals an effective charge equal to the charge of Cooper pairs, e^{*}=2e...
January 5, 2018: Physical Review Letters
Gun-Yeal Lee, Gwanho Yoon, Seung-Yeol Lee, Hansik Yun, Jaebum Cho, Kyookeun Lee, Hwi Kim, Junsuk Rho, Byoungho Lee
Reconstruction of light profiles with amplitude and phase information, called holography, is an attractive optical technology with various significant applications such as three-dimensional imaging and optical data storage. Subwavelength spatial control of both amplitude and phase of light is an essential requirement for an ideal hologram. However, traditional holographic devices suffer from their restricted capabilities of incomplete modulation in both amplitude and phase of visible light; this results in sacrifice of optical information and undesirable occurrences of critical noises in holographic images...
January 19, 2018: Nanoscale
Rinku Saran, Richard J Curry
Visible spectrum photodetector devices fabricated using molecular crystals of carbon C60 are reported. The devices operate efficiently, extending over and beyond the full visible light spectrum (300-710 nm) with a bias voltage tunable responsivity of 4 mA-0.5 mA W-1 . Across this range of wavelengths, the noise equivalent power of these devices remains below 102 nW Hz-1/2 , providing a detectivity of 107 Jones. The noise current in these devices is found to have a strong dependence on both bias voltage and frequency, varying by 4 orders of magnitude from 1 nA Hz-1/2 to 0...
January 19, 2018: Small
Thomas Münzel, Mette Sørensen, Frank P Schmidt, Erwin Schmidt, Sebastian Steven, Swenja Kröller-Schön, Andreas Daiber
Epidemiological studies have provided evidence that traffic noise exposure is linked to cardiovascular diseases such as arterial hypertension, myocardial infarction and stroke. Noise is a non-specific stressor that activates the autonomous nervous system and endocrine signaling. According to the noise reaction model introduced by Babisch and colleagues, chronic low levels of noise can cause so called non-auditory effects, such as disturbances of activity, sleep and communication, which can trigger a number of emotional responses, including annoyance and subsequent stress...
January 19, 2018: Antioxidants & Redox Signaling
Jonas Grimm, Maxim Dolgushev
We investigate the dynamics of fractals and other networks in a viscoelastic and active environment. The viscoelastic dynamics is modeled based on the generalized Langevin equation, where the activity is introduced to it by means of the exponentially correlated noise. The intramolecular interactions are taken into account by the bead-spring picture. The microscopic connectivity (studied in the form of Vicsek fractals, of dual Sierpiński gaskets, of NTD trees, and of a family of deterministic small-world networks) reveals itself in the multiscale monomeric dynamics, which shows vastly different behaviors in the active and passive baths...
January 19, 2018: Soft Matter
Ran Finkelstein, Eilon Poem, Ohad Michel, Ohr Lahad, Ofer Firstenberg
Future quantum photonic networks require coherent optical memories for synchronizing quantum sources and gates of probabilistic nature. We demonstrate a fast ladder memory (FLAME) mapping the optical field onto the superposition between electronic orbitals of rubidium vapor. Using a ladder-level system of orbital transitions with nearly degenerate frequencies simultaneously enables high bandwidth, low noise, and long memory lifetime. We store and retrieve 1.7-ns-long pulses, containing 0.5 photons on average, and observe short-time external efficiency of 25%, memory lifetime (1/e) of 86 ns, and below 10-4 added noise photons...
January 2018: Science Advances
Kaori Fujishiro, Anjum Hajat, Paul A Landsbergis, John D Meyer, Pamela J Schreiner, Joel D Kaufman
Research on racial/ethnic health disparities and socioeconomic position has not fully considered occupation. However, because occupations are racially patterned, certain occupational characteristics may explain racial/ethnic difference in health. This study examines the role of occupational characteristics in racial/ethnic disparities in all-cause mortality. Data are from a U.S. community-based cohort study (n=6342, median follow-up: 12.2 years), in which 893 deaths (14.1%) occurred. We estimated mortality hazard ratios (HRs) for African Americans, Hispanics, and Chinese Americans compared with whites...
December 2017: SSM—Population Health
Josep Sardanyés, Tomás Alarcón
Tumor cell populations are highly heterogeneous. Such heterogeneity, both at genotypic and phenotypic levels, is a key feature during tumorigenesis. How to investigate the impact of this heterogeneity in the dynamics of tumors cells becomes an important issue. Here we explore a stochastic model describing the competition dynamics between a pool of heterogeneous cancer cells with distinct phenotypes and healthy cells. This model is used to explore the role of demographic fluctuations on the transitions involving tumor clearance...
January 18, 2018: Scientific Reports
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