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https://www.readbyqxmd.com/read/28645731/aortic-backward-waves-rather-than-stiffness-account-for-independent-associations-between-pulse-pressure-amplification-and-left-ventricular-mass-in-a-young-to-middle-aged-sample
#1
Moekanyi J Sibiya, Gavin R Norton, Hendrik L Booysen, Grace Tade, Carlos D Libhaber, Imraan Ballim, Pinhas Sareli, Angela J Woodiwiss
A decreased aortic-to-brachial pulse pressure (PP) amplification, which is independently associated with cardiovascular outcomes, may index several aortic functional changes. However, that aortic functional change most likely to account for this effect is uncertain. In 706 randomly selected community participants of African ancestry with a mean age of 44.4 ± 18.2 years, we assessed aortic function using radial applanation tonometry and SphygmoCor software (including forward [Pf] and backward [Pb] wave separation analysis assuming a triangular flow waveform) and left ventricular mass index (LVMI) (echocardiography)...
June 2017: Journal of the American Society of Hypertension: JASH
https://www.readbyqxmd.com/read/28645730/the-relation-of-digital-vascular-function-to-cardiovascular-risk-factors-in-african-americans-using-digital-tonometry-the-jackson-heart-study
#2
Eric E McClendon, Solomon K Musani, Tandaw E Samdarshi, Sushant Khaire, Donny Stokes, Naomi M Hamburg, Koby Sheffy, Gary F Mitchell, Herman R Taylor, Emelia J Benjamin, Ervin R Fox
Digital vascular tone and function, as measured by peripheral arterial tonometry (PAT), are associated with cardiovascular risk and events in non-Hispanic whites. There are limited data on relations between PAT and cardiovascular risk in African-Americans. PAT was performed on a subset of Jackson Heart Study participants using a fingertip tonometry device. Resting digital vascular tone was assessed as baseline pulse amplitude. Hyperemic vascular response to 5 minutes of ischemia was expressed as the PAT ratio (hyperemic/baseline amplitude ratio)...
June 2017: Journal of the American Society of Hypertension: JASH
https://www.readbyqxmd.com/read/28645168/genomic-reconstruction-of-the-history-of-native-sheep-reveals-the-peopling-patterns-of-nomads-and-the-expansion-of-early-pastoralism-in-east-asia
#3
Yong-Xin Zhao, Ji Yang, Feng-Hua Lv, Xiao-Ju Hu, Xing-Long Xie, Min Zhang, Wen-Rong Li, Ming-Jun Liu, Yu-Tao Wang, Jin-Quan Li, Yong-Gang Liu, Yan-Ling Ren, Feng Wang, EEr Hehua, Juha Kantanen, Johannes Arjen Lenstra, Jian-Lin Han, Meng-Hua Li
China has a rich resource of native sheep (Ovis aries) breeds associated with historical movements of several nomadic societies. However, the history of sheep and the associated nomadic societies in ancient China remains poorly understood. Here, we studied the genomic diversity of Chinese sheep using genome-wide SNPs, mitochondrial and Y-chromosomal variations in more than 1,000 modern samples. Population genomic analyses combined with archaeological records and historical ethnic demographics data revealed genetic signatures of their origins, secondary expansions and admixtures, thereby revealing the peopling patterns of nomads and the expansion of early pastoralism in East Asia...
June 22, 2017: Molecular Biology and Evolution
https://www.readbyqxmd.com/read/28643832/metasurface-integrated-high-energy-efficient-and-high-linearly-polarized-ingan-gan-light-emitting-diode
#4
Miao Wang, Fuyang Xu, Yu Lin, Bing Cao, Linghua Chen, Chinhua Wang, Jianfeng Wang, Ke Xu
We proposed and demonstrated an integrated high energy efficient and high linearly polarized InGaN/GaN green LED grown on (0001) oriented sapphire with combined metasurface polarizing converter and polarizer system. It is different from those conventional polarized light emissions generated with plasmonic metallic grating in which at least 50% high energy loss occurs inherently due to high reflection of the transverse electric (TE) component of an electric field. A reflecting metasurface, with a two dimensional elliptic metal cylinder array (EMCA) that functions as a half-wave plate, was integrated at the bottom of a LED such that the back-reflected TE component, that is otherwise lost by a dielectric/metal bi-layered wire grids (DMBiWG) polarizer on the top emitting surface of the LED, can be converted to desired transverse magnetic (TM) polarized emission after reflecting from the metasurface...
June 23, 2017: Nanoscale
https://www.readbyqxmd.com/read/28639947/surface-electrocardiogram-could-atrioventricular-nodal-and-his-bundle-potentials-be-recorded-beat-by-beat-on-saah-electrocardiogram
#5
Qinghua Chang, Renguang Liu, Juan Chen
OBJECTIVE: The P-QRS-T wave on surface electrocardiogram (ECG) reflects the changes in atrial and ventricular electrical properties. However, the atrioventricular conduction system potentials cannot be recorded to date. This study aimed to explore the possibility of micropotential of the atrioventricular conduction system recorded by surface "SAN-Atrial-AVN-His (Saah) ECG." METHODS: We randomized 100 healthy volunteers (50 females and 50 males; mean age 25.12±1...
June 22, 2017: Anatolian Journal of Cardiology
https://www.readbyqxmd.com/read/28639151/central-arterial-function-measured-by-non-invasive-pulse-wave-analysis-is-abnormal-in-patients-with-duchenne-muscular-dystrophy
#6
Thomas D Ryan, John J Parent, Zhiqian Gao, Philip R Khoury, Elizabeth Dupont, Jennifer N Smith, Brenda Wong, Elaine M Urbina, John L Jefferies
Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder caused by mutation of dystrophin. Cardiovascular involvement includes dilated cardiomyopathy. Non-invasive assessment of vascular function has not been evaluated in DMD. We hypothesize arterial wave reflection is abnormal in patients with DMD. Pulse wave analysis was performed on DMD patients with a SphygmoCor SCOR-PVx System to determine central blood pressure and augmentation index (AIx) as an assessment of arterial wave reflection. Results were compared to a control group...
June 21, 2017: Pediatric Cardiology
https://www.readbyqxmd.com/read/28638910/dark-plasmonic-mode-based-perfect-absorption-and-refractive-index-sensing
#7
W H Yang, C Zhang, S Sun, J Jing, Q Song, S Xiao
Dark plasmonic resonances in metallic nanostructures are essential for many potential applications such as refractive index sensing, single molecule detection, nanolasers etc. However, it is difficult to excite the dark modes in optical experiments and thus the practical applications are severely limited. Herein, we demonstrate a simple method to experimentally excite the quadrupolar and higher-order plasmonic modes with normal incident light. By directionally depositing silver films onto the sidewalls of metal-covered one-dimensional grating, we have experimentally observed a series of asymmetrical resonances at the plasmonic ranges of silver gratings...
June 22, 2017: Nanoscale
https://www.readbyqxmd.com/read/28631528/determined-to-stop-longitudinal-analysis-of-the-desire-to-have-no-more-children-in-rural-mozambique
#8
Sarah R Hayford, Victor Agadjanian
Classic demographic theories conceptualize desired family size as a fixed goal that guides fertility intentions over the childbearing years. However, a growing body of research shows that fertility plans, even nominally long-term plans for completed childbearing, change in response to short-term conditions. Because of data limitations, much of this research has focused on low-fertility contexts, but short-term conditions are likely to be even more important in high-fertility contexts. This paper uses three waves of survey data collected in rural Mozambique to study predictors of the desire to stop childbearing in a context of relatively high fertility and high individual and social instability...
June 20, 2017: Population Studies
https://www.readbyqxmd.com/read/28630298/hypocretin-orexin-is-critical-in-sustaining-theta-gamma-rich-waking-behaviors-that-drive-sleep-need
#9
Anne Vassalli, Paul Franken
Hcrt gene inactivation in mice leads to behavioral state instability, abnormal transitions to paradoxical sleep, and cataplexy, hallmarks of narcolepsy. Sleep homeostasis is, however, considered unimpaired in patients and narcoleptic mice. We find that whereas Hcrt(ko/ko) mice respond to 6-h sleep deprivation (SD) with a slow-wave sleep (SWS) EEG δ (1.0 to 4.0 Hz) power rebound like WT littermates, spontaneous waking fails to induce a δ power reflecting prior waking duration. This correlates with impaired θ (6...
June 19, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28626613/modelling-environmental-drivers-of-black-band-disease-outbreaks-in-populations-of-foliose-corals-in-the-genus-montipora
#10
Carla C M Chen, David G Bourne, Christopher C Drovandi, Kerrie Mengersen, Bette L Willis, M Julian Caley, Yui Sato
Seawater temperature anomalies associated with warming climate have been linked to increases in coral disease outbreaks that have contributed to coral reef declines globally. However, little is known about how seasonal scale variations in environmental factors influence disease dynamics at the level of individual coral colonies. In this study, we applied a multi-state Markov model (MSM) to investigate the dynamics of black band disease (BBD) developing from apparently healthy corals and/or a precursor-stage, termed 'cyanobacterial patches' (CP), in relation to seasonal variation in light and seawater temperature at two reef sites around Pelorus Island in the central sector of the Great Barrier Reef...
2017: PeerJ
https://www.readbyqxmd.com/read/28624357/an-estimation-of-the-average-residence-times-and-onshore-offshore-diffusivities-of-beached-microplastics-based-on-the-population-decay-of-tagged-meso-and-macrolitter
#11
Hirofumi Hinata, Keita Mori, Kazuki Ohno, Yasuyuki Miyao, Tomoya Kataoka
Residence times of microplastics were estimated based on the dependence of meso- and macrolitter residence times on their upward terminal velocities (UTVs) in the ocean obtained by one- and two-year mark-recapture experiments conducted on Wadahama Beach, Nii-jima Island, Japan. A significant linear relationship between the residence time and UTV was found in the velocity range of about 0.3-0.9ms(-1), while there was no significant difference between the residence times obtained in the velocity range of about 0...
June 14, 2017: Marine Pollution Bulletin
https://www.readbyqxmd.com/read/28620767/a-novel-method-for-mouse-retinal-temperature-determination-based-on-erg-photoresponses
#12
Marja Pitkänen, Ossi Kaikkonen, Ari Koskelainen
This study introduces a novel retinal temperature determination method based on the temperature dependent properties of photoresponses recorded by electroretinography (ERG). The kinetics and amplitudes of ERG photoresponses depend on retinal temperature. Additionally, raising retinal temperature increases the probability of long-wavelength photon absorption, which manifests as temperature dependence of photoreceptor sensitivity. In this study we extract a number of features that represent these properties from the a- and b-waves of mouse ex vivo ERG flash responses and construct three multivariable regression models between temperature and the selected features...
June 15, 2017: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/28620212/shaping-electromagnetic-waves-using-software-automatically-designed-metasurfaces
#13
Qian Zhang, Xiang Wan, Shuo Liu, Jia Yuan Yin, Lei Zhang, Tie Jun Cui
We present a fully digital procedure of designing reflective coding metasurfaces to shape reflected electromagnetic waves. The design procedure is completely automatic, controlled by a personal computer. In details, the macro coding units of metasurface are automatically divided into several types (e.g. two types for 1-bit coding, four types for 2-bit coding, etc.), and each type of the macro coding units is formed by discretely random arrangement of micro coding units. By combining an optimization algorithm and commercial electromagnetic software, the digital patterns of the macro coding units are optimized to possess constant phase difference for the reflected waves...
June 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28618826/a-marchenko-equation-for-acoustic-inverse-source-problems
#14
Joost van der Neut, Jami L Johnson, Kasper van Wijk, Satyan Singh, Evert Slob, Kees Wapenaar
From acoustics to medical imaging and seismology, one strives to make inferences about the structure of complex media from acoustic wave observations. This study proposes a solution that is derived from the multidimensional Marchenko equation, to learn about the acoustic source distribution inside a volume, given a set of observations outside the volume. Traditionally, this problem has been solved by backpropagation of the recorded signals. However, to achieve accurate results through backpropagation, a detailed model of the medium should be known and observations should be collected along a boundary that completely encloses the volume of excitation...
June 2017: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/28618818/passive-bottom-reflection-loss-estimation-using-ship-noise-and-a-vertical-line-array
#15
Lanfranco Muzi, Martin Siderius, Christopher M Verlinden
An existing technique for passive bottom-loss estimation from natural marine surface noise (generated by waves and wind) is adapted to use noise generated by ships. The original approach-based on beamforming of the noise field recorded by a vertical line array of hydrophones-is retained; however, additional processing is needed in order for the field generated by a passing ship to show features that are similar to those of the natural surface-noise field. A necessary requisite is that the ship position, relative to the array, varies over as wide a range of steering angles as possible, ideally passing directly over the array to ensure coverage of the steepest angles...
June 2017: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/28618790/estimation-of-surface-impedance-at-oblique-incidence-based-on-sparse-array-processing
#16
Antoine Richard, Efren Fernandez-Grande, Jonas Brunskog, Cheol-Ho Jeong
A method is proposed to estimate the surface impedance of a large absorptive panel from free-field measurements with a spherical microphone array. The method relies on the reconstruction of the pressure and the particle velocity on the studied surface using an equivalent source method based on spherical array measurements. The sound field measured by the array is mainly composed of an incident and a reflected wave, so it can be represented as a spatially sparse problem. This makes it possible to use compressive sensing in order to enhance the resolution and the quality of the estimation...
June 2017: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/28618471/energy-dissipation-anomaly-in-systems-of-localized-waves
#17
Basile Gallet
We study the statistics of the power P dissipated by waves propagating in a one-dimensional disordered medium with damping coefficient ν. An operator imposes the wave amplitude at one end, therefore injecting a power P that balances dissipation. The typical realization of P vanishes for ν→0: Disorder leads to localization and total reflection of the wave energy back to the emitter, with negligible losses. More surprisingly, the mean dissipated power 〈P〉 averaged over the disorder reaches a finite limit for ν→0...
May 2017: Physical Review. E
https://www.readbyqxmd.com/read/28615684/flat-terahertz-reflective-focusing-metasurface-with-scanning-ability
#18
Huan Yi, Shi-Wei Qu, Bao-Jie Chen, Xue Bai, Kung Bo Ng, Chi Hou Chan
The ability to manipulate the propagation properties of electromagnetic waves, e.g., divergence, focusing, holography or deflection, is very significant in terahertz applications. Metasurfaces with flat structures are attractive for achieving such manipulations in terahertz band, as they feature low profile, lightweight, and ease of design and installation. Several types of terahertz reflective or transmitting metasurfaces with focusing function have been implemented recently, but none of them can provide scanning ability with controllable focus...
June 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28615043/-like-sugar-in-milk-reconstructing-the-genetic-history-of-the-parsi-population
#19
Gyaneshwer Chaubey, Qasim Ayub, Niraj Rai, Satya Prakash, Veena Mushrif-Tripathy, Massimo Mezzavilla, Ajai Kumar Pathak, Rakesh Tamang, Sadaf Firasat, Maere Reidla, Monika Karmin, Deepa Selvi Rani, Alla G Reddy, Jüri Parik, Ene Metspalu, Siiri Rootsi, Kurush Dalal, Shagufta Khaliq, Syed Qasim Mehdi, Lalji Singh, Mait Metspalu, Toomas Kivisild, Chris Tyler-Smith, Richard Villems, Kumarasamy Thangaraj
BACKGROUND: The Parsis are one of the smallest religious communities in the world. To understand the population structure and demographic history of this group in detail, we analyzed Indian and Pakistani Parsi populations using high-resolution genetic variation data on autosomal and uniparental loci (Y-chromosomal and mitochondrial DNA). Additionally, we also assayed mitochondrial DNA polymorphisms among ancient Parsi DNA samples excavated from Sanjan, in present day Gujarat, the place of their original settlement in India...
June 14, 2017: Genome Biology
https://www.readbyqxmd.com/read/28614365/modelling-community-control-strategies-to-protect-hospital-resources-during-an-influenza-pandemic-in-ottawa-canada
#20
Patrick Saunders-Hastings, Bryson Quinn Hayes, Robert Smith, Daniel Krewski
BACKGROUND: A novel influenza virus has emerged to produce a global pandemic four times in the past one hundred years, resulting in millions of infections, hospitalizations and deaths. There is substantial uncertainty about when, where and how the next influenza pandemic will occur. METHODS: We developed a novel mathematical model to chart the evolution of an influenza pandemic. We estimate the likely burden of future influenza pandemics through health and economic endpoints...
2017: PloS One
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