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frequency compression

Erik C Brown, Kunal Gupta, Christina Sayama
Lateral meningocele syndrome (LMS) is a rare genetic connective tissue disorder. It is associated with morphological changes similar to those of other connective tissue disorders, with the unique distinction of multiple, often bilateral and large, lateral meningoceles herniating through the spinal foramina. In some cases, these lateral meningoceles can cause pain and discomfort due to their presence within retroperitoneal tissues or cause direct compression of the spinal nerve root exiting the foramen; in some cases compression may also involve motor weakness...
December 2, 2016: Journal of Neurosurgery. Pediatrics
Wei Dong
Sound energy propagates in the cochlea through a forward-traveling or slow wave supported by the cochlear partition and fluid inertia. Additionally, cochlear models support traveling wave propagation in the reverse direction as the expected mechanism for conveying otoacoustic emissions out of the cochlea. Recently, however, this hypothesis has been questioned, casting doubt on the process by which otoacoustic emissions travel back out through the cochlea. The proposed alternative reverse travel path for emissions is directly through the fluids of the cochlea as a compression pressure in the form of a fast wave...
December 1, 2016: Journal of the Association for Research in Otolaryngology: JARO
Ning Pei, Leonard J Bond
Modeling and experiments are used to investigate Lamb wave propagation in the direction perpendicular to an applied stress. Sensitivity, in terms of changes in velocity, for both symmetrical and anti-symmetrical modes was determined. Codes were developed based on analytical expressions for waves in loaded plates and they were used to give wave dispersion curves. The experimental system used a pair of compression wave transducers on variable angle wedges, with set separation, and variable frequency tone burst excitation, on an aluminum plate 0...
November 2016: Journal of the Acoustical Society of America
Naushad Ansari, Anubha Gupta, Ananya Sen Gupta
Shallow water acoustic channel estimation techniques are presented at the intersection of time, frequency, and sparsity. Specifically, a mathematical framework is introduced that translates the problem of channel estimation to non-uniform sparse channel recovery in two-dimensional frequency domain. This representation facilitates disambiguation of slowly varying channel components against high-energy transients, which occupy different frequency ranges and also exhibit significantly different sparsity along their local distribution...
November 2016: Journal of the Acoustical Society of America
Marcio P Arruda, Patrick Brown, Gina Brown-Guedira, Allison M Krill, Carrie Thurber, Keith R Merrill, Bradley J Foresman, Frederic L Kolb
Fusarium head blight (FHB) is one of the most important wheat ( L.) diseases worldwide, and host resistance displays complex genetic control. A genome-wide association study (GWAS) was performed on 273 winter wheat breeding lines from the midwestern and eastern regions of the United States to identify chromosomal regions associated with FHB resistance. Genotyping-by-sequencing (GBS) was used to identify 19,992 single-nucleotide polymorphisms (SNPs) covering all 21 wheat chromosomes. Marker-trait associations were performed with different statistical models, the most appropriate being a compressed mixed linear model (cMLM) controlling for relatedness and population structure...
March 2016: Plant Genome
Chris D DiDomenico, Zhen Xiang Wang, Lawrence J Bonassar
The goal of this study was to characterize antibody penetration through cartilage tissue under mechanical loading. Mechanical stimulation aids in the penetration of some proteins, but this effect has not characterized molecules such as antibodies (>100 kDa), which may hold some clinical value for treating osteoarthritis (OA). For each experiment, fresh articular cartilage plugs were obtained and exposed to fluorescently labeled antibodies while under cyclic mechanical load in unconfined compression for several hours...
January 1, 2017: Journal of Biomechanical Engineering
R G Shah, M C Pierce, F H Silver
BACKGROUND: Collagenous tissues store, transmit and dissipate elastic energy during mechanical deformation. In skin, mechanical energy is stored during loading and then is dissipated, which protects skin from mechanical failure. Thus, energy storage (elastic properties) and dissipation (viscous properties) are important characteristics of extracellular matrices (ECMs) that support the cyclic loading of ECMs without tissue failure. METHODS: Uniaxial stress-strain measurements on decellularized human dermis have been made and compared to results of a non-destructive technique involving optical coherence tomography (OCT) combined with vibrational analysis...
November 27, 2016: Skin Research and Technology
Jie Lin, Ivane Jorjadze, Lea-Laetitia Pontani, Matthieu Wyart, Jasna Brujic
We report the first measurements of the effect of pressure on vibrational modes in emulsions, which serve as a model for soft frictionless spheres at zero temperature. As a function of the applied pressure, we find that the density of states D(ω) exhibits a low-frequency cutoff ω^{*}, which scales linearly with the number of extra contacts per particle δz. Moreover, for ω<ω^{*}, our results are consistent with D(ω)∼ω^{2}/ω^{*2}, a quadratic behavior whose prefactor is larger than what is expected from Debye theory...
November 11, 2016: Physical Review Letters
Tarnveer Singh Bhamra, Brian J Tighe
PURPOSE: This review summarises the way in which mechanical property measurements combined with clinical perception have influenced the last half century of materials evolution in contact lens development. METHODS: Literature concerning the use of in-vitro testing in assessment of the mechanical behaviour of contact lenses, and the mutual deformation of the lens material and ocular tissue was examined. Tensile measurements of historic and available hydrogel lenses have been collected, in addition to manufacturer-generated figures for the moduli of commercial silicone hydrogel lenses...
November 21, 2016: Contact Lens & Anterior Eye: the Journal of the British Contact Lens Association
Eve Piekarski, Teodora Chitiboi, Rebecca Ramb, Li Feng, Leon Axel
BACKGROUND: Arrhythmia can significantly alter the image quality of cardiovascular magnetic resonance (CMR); automatic detection and sorting of the most frequent types of arrhythmias during the CMR acquisition could potentially improve image quality. New CMR techniques, such as non-Cartesian CMR, can allow self-gating: from cardiac motion-related signal changes, we can detect cardiac cycles without an electrocardiogram. We can further use this data to obtain a surrogate for RR intervals (valley intervals: VV)...
November 25, 2016: Journal of Cardiovascular Magnetic Resonance
C Rada, S Oummou, F Merzouk, B Amarir, G Boussabnia, H Bougrini, D Benzaroual, S Elkarimi, M Elhattaoui
INTRODUCTION: Peripheral arterial disease is a marker of systemic atherosclerosis; it is associated with a high risk of cardiovascular disease. The aim of our study was to assess the prevalence of peripheral arterial disease by measuring the ankle-brachial pressure index in patients at high cardiovascular risk and to study the risk factors associated with this disease. METHODOLOGY: This was a descriptive and analytic cross-sectional study which focused on 370 patients seen at the medical consultation for atherosclerosis prevention...
November 16, 2016: Journal des Maladies Vasculaires
Matthew H Steinecker, Daniel J McCarron, Yuqi Zhu, David DeMille
We report the production of ultracold, trapped strontium monofluoride (SrF) molecules with number density and phase-space density significantly higher than previously achieved. These improvements are enabled by three distinct changes to our recently-demonstrated scheme for radio-frequency magneto-optical trapping of SrF: modification of the slowing laser beam geometry, addition of an optical pumping laser, and incorporation of a compression stage to the magneto-optical trap. With these improvements, we observe a trapped sample of SrF molecules at density 2...
November 8, 2016: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
Ellen M Adams, Dominique Verreault, Thilina Jayarathne, Richard E Cochran, Elizabeth A Stone, Heather C Allen
Transition metals are known to be enriched in organic-coated marine aerosols, but the impact these cations have on their surface properties is not well understood. Here the effect of Zn(2+) enrichment on the surface properties of a dipalmitoylphosphatidylcholine (DPPC) monolayer was investigated and compared to that of the alkaline earth metal Sr(2+), an ion not enriched in aerosols. Phase behavior of the DPPC film on concentrated aqueous solutions was probed with surface pressure-area isotherms while domain morphology was monitored with Brewster angle microscopy (BAM)...
November 30, 2016: Physical Chemistry Chemical Physics: PCCP
Matthew E Oetgen, Addison Goodley, Byungseok Yoo, Darryll J Pines, Adam H Hsieh
BACKGROUND: Rod fracture is a common complication of growing rods and can result in loss of correction, patient discomfort, and unplanned revision surgery. The ability to quantitate rod integrity at each lengthening would be advantageous to avoid this complication. We investigate the feasibility of applying structural health monitoring to evaluate the integrity of growing rods in vitro. METHODS: Single-rod titanium 4.5-mm growing rod constructs (n = 9), one screw proximally and one distally connected by in-line connectors, were assembled with pedicle screws fixed in polyethylene blocks...
January 2016: Spine Deformity
Xianming Liu, Gene Cheung, Xiaolin Wu, Debin Zhao
Given the prevalence of JPEG compressed images, optimizing image reconstruction from the compressed format remains an important problem. Instead of simply reconstructing a pixel block from the centers of indexed DCT coefficient quantization bins (hard decoding), soft decoding reconstructs a block by selecting appropriate coefficient values within the indexed bins with the help of signal priors. The challenge thus lies in how to define suitable priors and apply them effectively. In this paper, we combine three image priors-Laplacian prior for DCT coefficients, sparsity prior and graph-signal smoothness prior for image patches-to construct an efficient JPEG soft decoding algorithm...
November 10, 2016: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
Sami A Goussous, Mike T L Casford, Simon A Johnson, Paul B Davies
Molecular scale information about the structure of surfactants at interfaces underlies their application in consumer products. In this study the non-linear optical technique of Sum Frequency Generation (SFG) vibrational spectroscopy has been used to investigate the structure and temporal behaviour of two cationic surfactants used frequently in hair conditioners. SFG spectra of films of behenyltrimethylammonium methosulfate (BTMS) and behenyltrimethylammonium chloride (BTAC) were recorded at the air/water interface and on glass slides following Langmuir Blodgett (LB) deposition...
November 3, 2016: Journal of Colloid and Interface Science
Simon Henin, Dovid Fein, Eric Smouha, Lucas C Parra
BACKGROUND: Tinnitus correlates with elevated hearing thresholds and reduced cochlear compression. We hypothesized that reduced peripheral input leads to elevated neuronal gain resulting in the perception of a phantom sound. OBJECTIVE: The purpose of this pilot study was to test whether compensating for this peripheral deficit could reduce the tinnitus percept acutely using customized auditory stimulation. To further enhance the effects of auditory stimulation, this intervention was paired with high-definition transcranial direct current stimulation (HD-tDCS)...
2016: PloS One
Chaoying Tang, Biao Wang
Digital images have been extensively used in education, research, and entertainment. Many of these images, taken by consumer cameras, are compressed by the JPEG algorithm for effective storage and transmission. Blocking artifact is a well-known problem caused by this algorithm. Effective measurement of blocking artifacts plays an important role in the design, optimization, and evaluation of image compression algorithms. In this paper, we propose a no-reference objective blockiness measure, which is adaptive to high frequency component in an image...
2016: PloS One
Junya Yoshioka, Toru Yoshitomi, Tomoyuki Yasukawa, Keitaro Yoshimoto
In this study, we investigated the effect of positive dielectrophoresis (DEP) on gene expression in mesenchymal stem cells. When applying an alternating current voltage, human bone marrow derived mesenchymal stem cells (UE7T-13) exhibited a positive DEP, and were compressed onto the electrode surface. The constructed device can easily control the DEP force to the cells by changing the frequency. Interestingly, gene expressions of the cell differentiation marker in UE7T-13 cells and the mechanical stimulation-susceptible one were changed by applying a positive DEP...
2016: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
Kevin D Hill, Bryan H Goldstein, Michael J Angtuaco, Patricia Y Chu, Gregory A Fleming
OBJECTIVE: The aim of this study was to describe previously unrecognised or under-recognised adverse events associated with Melody® valve implantation. BACKGROUND: In rare diseases and conditions, it is typically not feasible to conduct large-scale safety trials before drug or device approval. Therefore, post-market surveillance mechanisms are necessary to detect rare but potentially serious adverse events. METHODS: We reviewed the United States Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database and conducted a structured literature review to evaluate adverse events associated with on- and off-label Melody® valve implantation...
November 10, 2016: Cardiology in the Young
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