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https://www.readbyqxmd.com/read/27933245/an-adaptive-switching-filter-based-on-approximated-variance-for-detection-of-impulse-noise-from-color-images
#1
K Pritamdas, Kh Manglem Singh, L Lolitkumar Singh
A new adaptive switching algorithm is presented where two adaptive filters are switched correspondingly for lower and higher noise ratio of the image. An adaptive center weighted vector median filter is used for the lower noise ratio whereas for higher noise ratio the noisy pixels are detected based on the comparison of the difference between the mean of the vector pixels in the window and the approximated variance of the vector pixels in the window. Then the window comprising the detected noisy pixel is further considered where the pixels are given exponential weights according to their similarity to the other neighboring pixels, spatially and radio metrically...
2016: SpringerPlus
https://www.readbyqxmd.com/read/27931172/biomechanical-response-of-the-infant-head-to-shaking-an-experimental-investigation
#2
Carol Jenny, Gina Bertocci, Tsuguhiro Fukuda, Nagarajan Rangarajan, Tariq Shams
Controversy exists regarding whether violent shaking is harmful to infants in the absence of impact. In this study, our objective was to characterize the biomechanical response of the infant head during shaking through use of an instrumented anthropomorphic test device (commonly referred to as a 'crash test dummy' or infant surrogate) representing a human infant and having improved biofidelity. A series of tests were conducted to simulate violent shaking of an infant surrogate. The Aprica 2.5 infant surrogate represented a 5th percentile Japanese newborn...
December 8, 2016: Journal of Neurotrauma
https://www.readbyqxmd.com/read/27929515/an-innovative-method-to-acquire-the-location-of-point-a-for-cervical-cancer-treatment-by-hdr-brachytherapy
#3
Liyun Chang, Sheng-Yow Ho, Shyh-An Yeh, Tsair-Fwu Lee, Pang-Yu Chen
Brachytherapy of local cervical cancer is generally accomplished through film-based treatment planning with the prescription directed to point A, which is invisible on images and is located at a high-dose gradient area. Through a standard reconstruction method by digitizing film points, the location error for point A would be 3mm with a condition of 30° curvature tandem, which is 10° away from the gantry rotation axis of a simulator, and has an 8.7 cm interval between the flange and the isocenter. To reduce the location error of the reconstructed point A, this paper proposes a method and demonstrates its accuracy...
November 8, 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/27929506/dose-reduction-in-ct-urography-and-vasculature-phantom-studies-using-model-based-iterative-reconstruction
#4
Leland Page, Wei Wei, Vikas Kundra, John Rong
To evaluate the feasibility of radiation dose reduction using model-based iterative reconstruction (MBIR) for evaluating the ureters and vasculature in a phantom, a tissue-equivalent CT dose phantom was scanned using a 64-channel CT scan-ner. Tubes of varying diameters filled with different dilutions of a contrast agent, simulating ureters or vessels, were inserted into the center of the phantom. Each combination was scanned using an existing renal protocol at 140 kVp or 120 kVp, yielding a display volumetric CT dose index (CTDIvol) of 24 mGy...
November 8, 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/27929485/difference-in-performance-between-3d-and-4d-cbct-for-lung-imaging-a-dose-and-image-quality-analysis
#5
Sheeba Thengumpallil, Kathleen Smith, Pascal Monnin, Jean Bourhis, François Bochud, Raphaël Moeckli
The study was to describe and to compare the performance of 3D and 4D CBCT imaging modalities by measuring and analyzing the delivered dose and the image quality. The 3D (Chest) and 4D (Symmetry) CBCT Elekta XVI lung IGRT protocols were analyzed. Dose profiles were measured with TLDs inside a dedicated phantom. The dosimetric indicator cone-beam dose index (CBDI) was evaluated. The image quality analysis was performed by assessing the contrast transfer function (CTF), the noise power spectrum (NPS) and the noise-equivalent quanta (NEQ)...
November 8, 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/27922990/robotically-assisted-thoracic-surgery-proposed-guidelines-for-privileging-and-credentialing
#6
Faiz Y Bhora, Adnan M Al-Ayoubi, Sadiq S Rehmani, Craig M Forleiter, Wissam N Raad, Scott G Belsley
OBJECTIVE: Increased use of robotically assisted thoracic surgery (RATS) necessitates effective credentialing guidelines to ensure safe outcomes. We provide a stepwise algorithm for granting privileges and credentials in RATS. This algorithm reflects graduated responsibility and complexity of the surgical procedures performed. Furthermore, it takes into account volume, outcomes, surgeon's competency, and appropriateness of robot usage. METHODS: We performed a literature review for available strategies to grant privileges and credentials for implementing robotic surgery...
December 5, 2016: Innovations: Technology and Techniques in Cardiothoracic and Vascular Surgery
https://www.readbyqxmd.com/read/27918346/electrical-stimulation-for-seizure-induction-and-functional-mapping-in-stereoelectroencephalography
#7
Agnès Trébuchon, Patrick Chauvel
The challenge in epilepsy surgery is to remove the epileptogenic zone without compromising postoperative function. Electrical stimulation (ES) was developed to identify with greater anatomical and physiological precision cortical structures essential to language and motor function. Because the language network is widely distributed in the left (dominant) hemisphere, and often varies among patients, brain mapping should delineate eloquent areas at the individual level. Although ES for language is commonly performed during a presurgical investigation, the procedure remains nonstandardized among centers, and differences between grids and intracerebral depth electrodes (stereoelectroencephalography) should be taken into account when comparing results from different series...
December 2016: Journal of Clinical Neurophysiology: Official Publication of the American Electroencephalographic Society
https://www.readbyqxmd.com/read/27918045/modeling-ion-permeation-through-a-bacterial-voltage-gated-calcium-channel-cavab-using-molecular-dynamics-simulations
#8
Jamal Adiban, Yousef Jamali, Hashem Rafii-Tabar
Activation of voltage-gated calcium channels by action potentials leads to the influx of Ca(2+) ions. In this study, the ion permeation characteristics in bacterial voltage-gated calcium (CaVAb) channels were investigated using molecular dynamics simulations. Furthermore, the potential of mean force (PMF) calculations was evaluated to determine the free energy profile for the permeation of cations (Ca(2+) and Na(+)) and anions (Cl(-)) in the CaVAb channel. The results showed that both Ca(2+) and Na(+) cations experienced a deep energy well, while the Cl(-) anion experienced a relatively high energy barrier at the center of the selectivity filter (site 2)...
December 5, 2016: Molecular BioSystems
https://www.readbyqxmd.com/read/27916634/lateral-heterogeneity-of-the-proton-potential-along-the-thylakoid-membranes-of-chloroplasts
#9
Alexey V Vershubskii, Boris V Trubitsin, Vladimir I Priklonskii, Alexander N Tikhonov
This work is devoted to critical analysis and reexamination of the problem of lateral heterogeneity of the trans-thylakoid pH difference (ΔpH=pHout-pHin) in thylakoid membranes of chloroplasts. Correct measurements of ΔpH may be complicated by nonuniform partitioning of the protons pumped into the lumen of granal (stacked) and stroma-exposed thylakoids. We have compared results of ΔpH estimations in isolated bean chloroplasts by two different methods. One of the methods is based on the use of pH-sensitive spin-probes...
December 1, 2016: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/27914853/monitoring-the-fitness-of-antiviral-resistant-influenza-strains-during-an-epidemic-a-mathematical-modelling-study
#10
Kathy Leung, Marc Lipsitch, Kwok Yung Yuen, Joseph T Wu
BACKGROUND: Antivirals (eg, oseltamivir) are important for mitigating influenza epidemics. In 2007, an oseltamivir-resistant influenza seasonal A H1N1 strain emerged and spread to global fixation within 1 year. This event showed that antiviral-resistant (AVR) strains can be intrinsically more transmissible than their contemporaneous antiviral-sensitive (AVS) counterpart. Surveillance of AVR fitness is therefore essential. Our objective was to develop a simple method for estimating AVR fitness from surveillance data...
November 30, 2016: Lancet Infectious Diseases
https://www.readbyqxmd.com/read/27914399/dynamics-and-acoustics-of-a-spherical-bubble-rising-under-gravity-in-an-inviscid-liquid
#11
Giorgio Riccardi, Enrico De Bernardis
The rising motion and the acoustic emission of a pulsating spherical gas/vapour bubble in an isochoric, inviscid liquid are investigated. The motion is driven by the uniform and constant force field due to the gravity. The liquid is assumed at rest at the initial time. Unlike previous work on this subject, the mass of the bubble is not neglected, so that the bubble motion is accurately simulated also in the presence of large volume variations. After developing the relationships between the bubble motion to the liquid flow, a system of two nonlinear ordinary differential equations (ODEs) for the radius and the position of the center of mass of the bubble is written...
September 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27914386/single-sensor-cue-counting-population-density-estimation-average-probability-of-detection-of-broadband-clicks
#12
Elizabeth T Küsel, Martin Siderius, David K Mellinger
Odontocete echolocation clicks have been used as a preferred cue for density estimation using single-sensor data sets, requiring estimation of detection probability as a function of range. Many such clicks can be very broadband in nature, with 10-dB bandwidths of 20-40 kHz or more. Detection distances are not readily obtained from single-sensor data. Here, the average detection probability is estimated in a Monte Carlo simulation using the passive sonar equation along with transmission loss calculations to estimate the signal-to-noise ratio (SNR) of tens of thousands of click realizations...
September 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27914385/beamforming-pointing-error-of-a-triaxial-velocity-sensor-under-gain-uncertainties
#13
Tsair-Chuan Lin, Kainam Thomas Wong, Macario O Cordel, Joel Paz Ilao
A "triaxial velocity sensor" consists of three uniaxial velocity sensors, which are nominally identical, orthogonally oriented among themselves, and co-centered at one point in space. A triaxial velocity sensor measures the acoustic particle velocity vector, by its three Cartesian components, individually component-by-component, thereby offering azimuth-elevation two-dimensional spatial directivity, despite the physical compactness that comes with the collocation of its three components. This sensing system's azimuth-elevation beam-pattern has been much analyzed in the open literature, but only for an idealized case of the three uniaxial velocity sensors being exactly identical in gain...
September 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27914323/quantitative-farm-to-fork-human-norovirus-exposure-assessment-of-individually-quick-frozen-raspberries-and-raspberry-puree
#14
L Jacxsens, A Stals, A De Keuckelaere, B Deliens, A Rajkovic, M Uyttendaele
A quantitative human norovirus (NoV) exposure model describing transmission of NoV during pre-harvest, harvest and further processing of soft red fruits exemplified by raspberries is presented. The outcomes of the model demonstrate the presence of NoV in raspberry puree or individual quick frozen (IQF) raspberry fruits and were generated by Monte Carlo simulations by combining GoldSim® and @Risk® software. Input data were collected from scientific literature, observational studies and assumptions. NoV contamination of soft red fruits is assumed to take place at farms by application of contaminated water for pesticides dilution or by berries' pickers shedding NoV...
November 21, 2016: International Journal of Food Microbiology
https://www.readbyqxmd.com/read/27914012/biomechanical-investigation-of-titanium-elastic-nail-prebending-for-treating-diaphyseal-long-bone-fractures
#15
Yen-Nien Chen, Pei-Yuan Lee, Chih-Wei Chang, Yi-Hung Ho, Yao-Te Peng, Chih-Han Chang, Chun-Ting Li
This study numerically investigated the deformation of titanium elastic nails prebent at various degrees during implantation into the intramedullary canal of fractured bones and the mechanism by which this prebending influenced the stability of the fractured bone. Three degrees of prebending the implanted portions of the nails were used: equal to, two times, and three times the diameter of the intramedullary canal. Furthermore, a simulated diaphyseal fracture with a 5-mm gap was created in the middle shaft portion of the bone fixed with two elastic nails in a double C-type configuration...
December 2, 2016: Australasian Physical & Engineering Sciences in Medicine
https://www.readbyqxmd.com/read/27913901/3d-active-passive-response-of-human-knee-joint-in-gait-is-markedly-altered-when-simulated-as-a-planar-2d-joint
#16
H Marouane, A Shirazi-Adl, M Adouni
Musculoskeletal models of the lower extremity make a number of important assumptions when attempting to estimate muscle forces and tibiofemoral compartmental loads in activities such as gait. The knee is commonly idealized as a planar 2D joint in the sagittal plane with no consideration of motions and equilibrium in remaining planes. With muscle forces predicted, the static equilibrium in the frontal plane is then used to estimate compartmental loads neglecting also joint passive resistance and assuming condylar contact centers...
December 2, 2016: Biomechanics and Modeling in Mechanobiology
https://www.readbyqxmd.com/read/27913334/switchable-and-tunable-baw-duplexer-based-on-ferroelectric-material
#17
Almonir Abdulgader Mansour, Thottam S Kalkur
A switchable and tunable bulk acoustic wave (BAW) duplexer for RF applications is presented in this paper. The fabricated BAW duplexer was built on sapphire substrate using solidly mounted resonators. A metal-organic solution deposition technique was used to form resonators with barium strontium titanate (BST) thin film and six layers of silicon dioxide and tantalum oxide as Bragg reflector. By applying dc bias, the BST thin film shows an electrostrictive effect, and the two filter paths of the BAW duplexer switch to a bandpass response with center frequencies at 4...
December 2016: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/27911799/mechanism-of-the-intrinsic-arginine-finger-in-heterotrimeric-g-proteins
#18
Daniel Mann, Christian Teuber, Stefan A Tennigkeit, Grit Schröter, Klaus Gerwert, Carsten Kötting
Heterotrimeric G proteins are crucial molecular switches that maintain a large number of physiological processes in cells. The signal is encoded into surface alterations of the Gα subunit that carries GTP in its active state and GDP in its inactive state. The ability of the Gα subunit to hydrolyze GTP is essential for signal termination. Regulator of G protein signaling (RGS) proteins accelerates this process. A key player in this catalyzed reaction is an arginine residue, Arg178 in Gαi1, which is already an intrinsic part of the catalytic center in Gα in contrast to small GTPases, at which the corresponding GTPase-activating protein (GAP) provides the arginine "finger...
November 28, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27910905/magnitude-and-pattern-of-arctic-warming-governed-by-the-seasonality-of-radiative-forcing
#19
R Bintanja, F Krikken
Observed and projected climate warming is strongest in the Arctic regions, peaking in autumn/winter. Attempts to explain this feature have focused primarily on identifying the associated climate feedbacks, particularly the ice-albedo and lapse-rate feedbacks. Here we use a state-of-the-art global climate model in idealized seasonal forcing simulations to show that Arctic warming (especially in winter) and sea ice decline are particularly sensitive to radiative forcing in spring, during which the energy is effectively 'absorbed' by the ocean (through sea ice melt and ocean warming, amplified by the ice-albedo feedback) and consequently released to the lower atmosphere in autumn and winter, mainly along the sea ice periphery...
December 2, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27910515/proton-pinhole-imaging-on-the-national-ignition-facility
#20
A B Zylstra, H-S Park, J S Ross, F Fiuza, J A Frenje, D P Higginson, C Huntington, C K Li, R D Petrasso, B Pollock, B Remington, H G Rinderknecht, D Ryutov, F H Séguin, D Turnbull, S C Wilks
Pinhole imaging of large (mm scale) carbon-deuterium (CD) plasmas by proton self-emission has been used for the first time to study the microphysics of shock formation, which is of astrophysical relevance. The 3 MeV deuterium-deuterium (DD) fusion proton self-emission from these plasmas is imaged using a novel pinhole imaging system, with up to five different 1 mm diameter pinholes positioned 25 cm from target-chamber center. CR39 is used as the detector medium, positioned at 100 cm distance from the pinhole for a magnification of 4 ×...
November 2016: Review of Scientific Instruments
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