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https://www.readbyqxmd.com/read/28618811/vocal-repertoire-of-long-finned-pilot-whales-globicephala-melas-in-northern-norway
#1
Heike Vester, Sarah Hallerberg, Marc Timme, Kurt Hammerschmidt
The knowledge of the vocal repertoire of pilot whales is very limited. In this paper, the vocal repertoire of long-finned pilot whales recorded during different encounters in the Vestfjord in northern Norway between November 2006 and August 2010 are described. Sounds were analysed using two different methods: (1) an observer-based audio-visual inspection of FFT-derived spectrograms, with which, besides a general variety of clicks, buzzes, nonharmonic sounds, and whistles, 129 different distinct call types and 25 subtypes were distinguished...
June 2017: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/28618587/general-scaling-relations-for-locomotion-in-granular-media
#2
James Slonaker, D Carrington Motley, Qiong Zhang, Stephen Townsend, Carmine Senatore, Karl Iagnemma, Ken Kamrin
Inspired by dynamic similarity in fluid systems, we have derived a general dimensionless form for locomotion in granular materials, which is validated in experiments and discrete element method (DEM) simulations. The form instructs how to scale size, mass, and driving parameters in order to relate dynamic behaviors of different locomotors in the same granular media. The scaling can be derived by assuming intrusion forces arise from resistive force theory or equivalently by assuming the granular material behaves as a continuum obeying a frictional yield criterion...
May 2017: Physical Review. E
https://www.readbyqxmd.com/read/28618469/collisional-dissipation-rate-in-shearing-flows-of-granular-liquid-crystals
#3
Diego Berzi, Nha Thai-Quang, Yu Guo, Jennifer Curtis
We make use of discrete-element-method numerical simulations of inelastic frictionless cylinders in simple shearing at different length-to-diameter ratios and solid volume fractions to analyze the rate of collisional dissipation of the fluctuation kinetic energy. We show that the nonspherical geometry of the particles is responsible, by inducing rotation, for increasing the dissipation rate of the fluctuation kinetic energy with respect to that for frictionless spheres. We also suggest that the partial alignment of the cylinders induced by shearing concurs with the particle inelasticity in generating correlation in the velocity fluctuations and thus affecting the collisional dissipation rate as the solid volume fraction increases...
May 2017: Physical Review. E
https://www.readbyqxmd.com/read/28615743/edge-based-nonlinear-diffusion-for-finite-element-approximations-of-convection-diffusion-equations-and-its-relation-to-algebraic-flux-correction-schemes
#4
Gabriel R Barrenechea, Erik Burman, Fotini Karakatsani
For the case of approximation of convection-diffusion equations using piecewise affine continuous finite elements a new edge-based nonlinear diffusion operator is proposed that makes the scheme satisfy a discrete maximum principle. The diffusion operator is shown to be Lipschitz continuous and linearity preserving. Using these properties we provide a full stability and error analysis, which, in the diffusion dominated regime, shows existence, uniqueness and optimal convergence. Then the algebraic flux correction method is recalled and we show that the present method can be interpreted as an algebraic flux correction method for a particular definition of the flux limiters...
2017: Numer Math (Heidelb)
https://www.readbyqxmd.com/read/28609299/arterial-waveguide-model-for-shear-wave-elastography-implementation-and-in-vitro-validation
#5
Ali Vaziri Astaneh, Matthew W Urban, Wilkins Aquino, James F Greenleaf, Murthy N Guddati
Arterial stiffness is found to be an early indicator of many cardiovascular diseases. Among various techniques, shear wave elastography has emerged as a promising tool for estimating local arterial stiffness through the observed dispersion of guided waves. In this paper, we develop efficient models for the computational simulation of guided wave dispersion in arterial walls. The models are capable of considering fluid-loaded tubes, immersed in fluid or embedded in a solid, which are encountered in in vitro/ex vivo, and in vivo experiments...
July 7, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28599536/effect-of-a-serrated-trailing-edge-on-sound-radiation-from-nearby-quadrupoles
#6
Mahmoud Karimi, Paul Croaker, Roger Kinns, Nicole Kessissoglou
A periodic boundary element technique is implemented to study the noise reduction capability of a plate with a serrated trailing edge under quadrupole excitation. It is assumed for this purpose that the quadrupole source tensor is independent of the trailing edge configuration and that the effect of the trailing edge shape is to modify sound radiation from prescribed boundary layer sources. The flat plate is modelled as a continuous structure with a finite repetition of small spanwise segments. The matrix equation formulated by the periodic boundary element method for this 3D acoustic scattering problem is represented as a block Toeplitz matrix...
May 2017: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/28593458/sensitivity-based-adaptive-mesh-refinement-collocation-method-for-dynamic-optimization-of-chemical-and-biochemical-processes
#7
Long Xiao, Ping Liu, Xinggao Liu, Zeyin Zhang, Yalin Wang, Chunhua Yang, Weihua Gui, Xu Chen, Bochao Zhu
Collocation on finite element (CFE) is an effective simultaneous method of dynamic optimization to increase the profitability or productivity of industrial process. The approach needs to select an optimal mesh of time interval to balance the computational cost with desired solution. A new CFE approach with non-uniform refinement procedure based on the sensitivity analysis for dynamic optimization problems is, therefore, proposed, where a subinterval is further refined if the obtained control parameters have significant effect on the performance index...
June 7, 2017: Bioprocess and Biosystems Engineering
https://www.readbyqxmd.com/read/28587636/recognizing-rna-structural-motifs-in-ht-selex-data-for-ribosomal-protein-s15
#8
Shermin Pei, Betty L Slinger, Michelle M Meyer
BACKGROUND: Proteins recognize many different aspects of RNA ranging from single stranded regions to discrete secondary or tertiary structures. High-throughput sequencing (HTS) of in vitro selected populations offers a large scale method to study RNA-proteins interactions. However, most existing analysis methods require that the binding motifs are enriched in the population relative to earlier rounds, and that motifs are found in a loop or single stranded region of the potential RNA secondary structure...
June 6, 2017: BMC Bioinformatics
https://www.readbyqxmd.com/read/28579077/phylogenomic-analysis-of-lake-malawi-cichlid-fishes-further-evidence-that-the-three-stage-model-of-diversification-does-not-fit
#9
Christopher Darrin Hulsey, Jimmy Zheng, Brant C Faircloth, Axel Meyer, Michael E Alfaro
Adaptive radiations could often occur in discrete stages. For instance, the species flock of ∼1000 species of Lake Malawi cichlid fishes might have only diverged once between rocky and sandy environments during the initial stage of their diversification. All further diversification within the rock-dwelling (mbuna) or sand-dwelling (utaka) cichlids would have occurred during a subsequent second stage of extensive trophic evolution that was followed by a third stage of sexual trait divergence. We provide an improved phylogenetic framework for Malawi cichlids to test this three-stage hypothesis based on newly reconstructed phylogenetic relationships among 32 taxonomically disparate Malawi cichlids species...
June 1, 2017: Molecular Phylogenetics and Evolution
https://www.readbyqxmd.com/read/28574733/mechanistic-investigation-of-mixing-segregation-of-ordered-mixtures-experiments-numerical-simulations
#10
Saurabh Sarkar, Bruna Minatovicz, Kyrre Thalberg, Bodhisattwa Chaudhuri
Pulmonary delivery of cohesive and micronized drugs through Dry Powder Inhalers (DPIs) is traditionally achieved through the formation of ordered mixtures. In order to improve the mechanistic understanding of formation of ordered mixtures, the system consisting of micronized lactose (AZFL, representative of an active pharmaceutical ingredient) and a coarse particle carrier (LH100) is investigated as a function of different process and material variables in a high shear mixer (HSM) and in a low shear double cone (DCN) blender, using both experimental and numerical methods...
June 2, 2017: Drug Development and Industrial Pharmacy
https://www.readbyqxmd.com/read/28553011/computational-fluid-dynamics-discrete-element-method-cfd-dem-study-of-mass-transfer-mechanisms-in-riser-flow
#11
Álvaro E Carlos Varas, E A J F Peters, J A M Kuipers
We report a computational fluid dynamics-discrete element method (CFD-DEM) simulation study on the interplay between mass transfer and a heterogeneous catalyzed chemical reaction in cocurrent gas-particle flows as encountered in risers. Slip velocity, axial gas dispersion, gas bypassing, and particle mixing phenomena have been evaluated under riser flow conditions to study the complex system behavior in detail. The most important factors are found to be directly related to particle cluster formation. Low air-to-solids flux ratios lead to more heterogeneous systems, where the cluster formation is more pronounced and mass transfer more influenced...
May 17, 2017: Industrial & Engineering Chemistry Research
https://www.readbyqxmd.com/read/28552920/an-alternative-3d-numerical-method-to-study-the-biomechanical-behaviour-of-the-human-inner-ear-semicircular-canal
#12
Carla F Santos, Jorge Belinha, Fernanda Gentil, Marco Parente, Renato N Jorge
PURPOSE: The vestibular system is the part of the inner ear responsible for balance. Vertigo and dizziness are generally caused by vestibular disorders and are very common symptoms in people over 60 years old. One of the most efficient treatments at the moment is vestibular rehabilitation, permitting to improve the symptoms. However, this rehabilitation therapy is a highly empirical process, which needs to be enhanced and better understood. METHODS: This work studies the vestibular system using an alternative computational approach...
2017: Acta of Bioengineering and Biomechanics
https://www.readbyqxmd.com/read/28541192/real-time-error-control-for-surgical-simulation
#13
Huu Phuoc Bui, Satyendra Tomar, Hadrien Courtecuisse, Stephane Cotin, Stephane Bordas
OBJECTIVE: To present the first real-time a posteriori error-driven adaptive finite element approach for realtime simulation and to demonstrate the method on a needle insertion problem. METHODS: We use corotational elasticity and a frictional needle/tissue interaction model. The problem is solved using finite elements within SOFA1. The refinement strategy relies upon a hexahedron-based finite element method, combined with a posteriori error estimation driven local h-refinement, for simulating soft tissue deformation...
May 23, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28516345/performance-and-cost-evaluation-of-health-information-systems-using-micro-costing-and-discrete-event-simulation
#14
Olfa Rejeb, Claire Pilet, Sabri Hamana, Xiaolan Xie, Thierry Durand, Saber Aloui, Anne Doly, Pierre Biron, Lionel Perrier, Vincent Augusto
Innovation and health-care funding reforms have contributed to the deployment of Information and Communication Technology (ICT) to improve patient care. Many health-care organizations considered the application of ICT as a crucial key to enhance health-care management. The purpose of this paper is to provide a methodology to assess the organizational impact of high-level Health Information System (HIS) on patient pathway. We propose an integrated performance evaluation of HIS approach through the combination of formal modeling using the Architecture of Integrated Information Systems (ARIS) models, a micro-costing approach for cost evaluation, and a Discrete-Event Simulation (DES) approach...
May 17, 2017: Health Care Management Science
https://www.readbyqxmd.com/read/28510575/electro-mechanical-dynamics-of-spiral-waves-in-a-discrete-2d-model-of-human-atrial-tissue
#15
Paul Brocklehurst, Haibo Ni, Henggui Zhang, Jianqiao Ye
We investigate the effect of mechano-electrical feedback and atrial fibrillation induced electrical remodelling (AFER) of cellular ion channel properties on the dynamics of spiral waves in a discrete 2D model of human atrial tissue. The tissue electro-mechanics are modelled using the discrete element method (DEM). Millions of bonded DEM particles form a network of coupled atrial cells representing 2D cardiac tissue, allowing simulations of the dynamic behaviour of electrical excitation waves and mechanical contraction in the tissue...
2017: PloS One
https://www.readbyqxmd.com/read/28493110/bem-based-simulation-of-lung-respiratory-deformation-for-ct-guided-biopsy
#16
Dong Chen, Weisheng Chen, Lipeng Huang, Xuegang Feng, Terry Peters, Lixu Gu
PURPOSE: Accurate and real-time prediction of the lung and lung tumor deformation during respiration are important considerations when performing a peripheral biopsy procedure. However, most existing work focused on offline whole lung simulation using 4D image data, which is not applicable in real-time image-guided biopsy with limited image resources. In this paper, we propose a patient-specific biomechanical model based on the boundary element method (BEM) computed from CT images to estimate the respiration motion of local target lesion region, vessel tree and lung surface for the real-time biopsy guidance...
May 10, 2017: International Journal of Computer Assisted Radiology and Surgery
https://www.readbyqxmd.com/read/28472465/precise-integration-of-inducible-transcriptional-elements-priite-enables-absolute-control-of-gene-expression
#17
Rita Pinto, Lars Hansen, John Hintze, Raquel Almeida, Sylvester Larsen, Mehmet Coskun, Johanne Davidsen, Cathy Mitchelmore, Leonor David, Jesper Thorvald Troelsen, Eric Paul Bennett
Tetracycline-based inducible systems provide powerful methods for functional studies where gene expression can be controlled. However, the lack of tight control of the inducible system, leading to leakiness and adverse effects caused by undesirable tetracycline dosage requirements, has proven to be a limitation. Here, we report that the combined use of genome editing tools and last generation Tet-On systems can resolve these issues. Our principle is based on precise integration of inducible transcriptional elements (coined PrIITE) targeted to: (i) exons of an endogenous gene of interest (GOI) and (ii) a safe harbor locus...
May 4, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28464970/advanced-identification-and-quantification-of-in-bearing-minerals-by-scanning-electron-microscope-based-image-analysis
#18
Kai Bachmann, Max Frenzel, Joachim Krause, Jens Gutzmer
The identification and accurate characterization of discrete grains of rare minerals in sulfide base-metal ores is usually a cumbersome procedure due to the small grain sizes (typically <10 μm) and complex mineral assemblages in the material. In this article, a new strategy for finding and identifying indium minerals, and quantifying their composition and abundance is presented, making use of mineral liberation analysis (MLA) and electron probe microanalysis (EPMA). The method was successfully applied to polymetallic massive sulfide ores from the Neves-Corvo deposit in Portugal...
May 3, 2017: Microscopy and Microanalysis
https://www.readbyqxmd.com/read/28464438/social-skills-training-for-children-with-autism-spectrum-disorder-using-a-robotic-behavioral-intervention-system
#19
Sang-Seok Yun, JongSuk Choi, Sung-Kee Park, Gui-Young Bong, HeeJeong Yoo
We designed a robot system that assisted in behavioral intervention programs of children with autism spectrum disorder (ASD). The eight-session intervention program was based on the discrete trial teaching protocol and focused on two basic social skills: eye contact and facial emotion recognition. The robotic interactions occurred in four modules: training element query, recognition of human activity, coping-mode selection, and follow-up action. Children with ASD who were between 4 and 7 years old and who had verbal IQ ≥ 60 were recruited and randomly assigned to the treatment group (TG, n = 8, 5...
May 2, 2017: Autism Research: Official Journal of the International Society for Autism Research
https://www.readbyqxmd.com/read/28433790/a-strain-mediated-corrosion-model-for-bioabsorbable-metallic-stents
#20
E Galvin, D O'Brien, C Cummins, B J Mac Donald, C Lally
This paper presents a strain-mediated phenomenological corrosion model, based on the discrete finite element modelling method which was developed for use with the ANSYS Implicit finite element code. The corrosion model was calibrated from experimental data and used to simulate the corrosion performance of a WE43 magnesium alloy stent. The model was found to be capable of predicting the experimentally observed plastic strain-mediated mass loss profile. The non-linear plastic strain model, extrapolated from the experimental data, was also found to adequately capture the corrosion-induced reduction in the radial stiffness of the stent over time...
April 19, 2017: Acta Biomaterialia
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