bluuebunny/crossref_metadata_2025 huggingface dataset:
Cytomechanical perturbations induced by pulsed ultrasound and acoustic cavitation
Authors: Yu Alfred C. , Wan Jennifer M.
Published: October 2018

The therapeutic applicability of ultrasound is perhaps well demonstrated with the advent of high-intensity focused ultrasound (HIFU) that works by rapidly heating tissues to induce ablation. Ultrasound also holds tremendous therapeutic potential at low intensities that are near or below the clinical diagnosis limit (720 mW/cm2 spatial-peak time-averaged intensity, as set forth by FDA), presumably acting through a mechanical interaction pathway. To establish the therapeutic potential of low-intensity ultrasound, it is fundamentally important to characterize its biophysical interactions with living cells. This talk shall present a series of non-thermal wave-matter interactions of low-intensity pulsed ultrasound. The biophysical interactions between low-intensity ultrasound and living cells will particularly be demonstrated through direct observations acquired using live optical and confocal microscopy tools. We will also examine the scenario where microbubbles are introduced as agents to induce acoustic cavitation. Temporary membrane perforation may be readily achieved in this case (often referred to as sonoporation), and it has been tipped as an emerging paradigm for drug/gene delivery. Epitomizing observations on this process will be shown during the presentation.
Acoustic fields and forces in drug delivery applications
Authors: Allen John S.
Published: October 2018

For ultrasound drug delivery applications, the ability to manipulate and move both the carriers and their payloads provides a way of increasing over efficacy. Both primary and secondary acoustic radiation forces have been used though the optimal acoustic forcing parameters and delivery system are subject to on-going investigations. The primary radiation or Bjerknes force occurs from inhomogeneous propagation of the acoustic field and has been used to direct targeted ultrasound contrast agents or particles in vessels towards endothelial cells or pathological targets at the vessel wall. Secondary Bjerknes forces arise from multiple scattering effects between neighboring particles. For corresponding attractive force regimes, greater particle congregation is possible. Overview of theoretical background and predictions of the acoustic radiation forces is given. The formulation of particle translation by primary radiation in the long wavelength limit is discussed with respect to unsteady drag. Pair wise interaction between particles moving in tandem is compared with formulations for along the lines of center. Nonstationary forcing with respect to amplitude modulation or frequency (chirp) alters the attraction and repulsion regimes compared to continuous forcing. Cellular transport for payloads may be enhanced using more optimally tuned pulse sequences.
String synthesis using individually modeled termination scattering filters
Authors: Rau Mark , Smith Julius O. , Abel Jonathan S.
Published: October 2018

In the context of digital waveguide synthesis of string instruments, strings are modeled as pairs of digital waveguides which encounter a scattering junction at each boundary. The string scattering junction at the bridge can be modeled to match the measured driving point admittance at the bridge of a physical instrument, and is used in calculating the radiated sound. The string termination at the nut, or fingering end of the string, is typically modeled with a single scalar attenuation, independent of the fingering. However, driving point admittance measurements are presented confirming that string reflectance is a function of both frequency and fingering. A model is proposed which uses a unique, frequency-dependent string reflection scattering junction for each fingering position. The fingering location scattering junctions are calculated using a modal architecture based on driving point admittance measurements made on an acoustic guitar at the bridge, nut, and frets 1 through 13. These synthesized strings are compared to recordings of the physical instrument, as well as to the widely used scalar attenuation model.
Noise reduction using metamaterials and metasurfaces
Authors: Jing Yun
Published: October 2018

We are surrounded by noise. Planes, trains, cars, crowds, cooling fans — just about everything is a potential source of noise. Traditional noise abatement methods have a number of limitations and they are particularly ineffective for low frequency noise. As we are becoming increasingly aware of the noise pollution issue, there is a pressing need to develop novel materials for more effective noise reduction. In this talk, I will give an overview of recent development on noise reduction using metamaterials or metasurfaces. I will cover structures such as decorated membrane resonators, hybrid resonators, and coiled Helmholtz resonators.
Correlating dynamical properties of organic aerogel with increased sound insulation of sandwich wallboard systems
Authors: Xiang Ning , Whitney Mathew A. , Malakooti Sadeq , Churu Habel G. , Leventis Nicholas , Lu Hongbing
Published: October 2018

Low thermal conductivity of classical aerogels has long been exploited, while their dynamic properties are yet to be further investigated. This work investigates a new class of acoustic materials based on porous hierarchical three-dimensional assemblies of organic nanoparticles. Primary polymer nanoparticles are formed via chemical reactions in solution and self-assemble to fractal porous secondary particles, which in turn become the fundamental building blocks of larger globular, fibrous or hybrid structures that form the microscopic network of highly porous monolithic materials referred to as polymer-crosslinked (or X-) aerogels. Their low-cost, thin-panel form has found potential applications as constrained damping layers integrated into gypsum wallboards. The standardized chamber-based random-incident tests demonstrate drastically increased sound transmission losses without significantly increasing the board thickness and weight when light-weight X-aerogel panels of less than 1 cm in thickness are integrated into gypsum wallboards in sandwich structure. For better understanding of its excellent effect as constrained damping layers, this paper discusses experimental investigations on broadband dynamic properties of X-aerogels with the intention to correlate their intriguing dynamic properties with increased sound insulations which will have high potentials as emerging building materials for advanced noise and vibration controls and beyond.
Complex frequency analysis of the scattering matrix for the design of perfect absorbers in reflection and transmission problems
Authors: Jiménez Noé , Romero-Garcìa Vicente , Pagneux Vincent , Groby Jean-Philippe
Published: October 2018

The design of deep-subwavelength structures for low frequency sound perfect absorption is challenging. Subwavelength perfect absorption implies increasing of the density of states at low frequency while maintaining impedance matching to the surrounding medium. Therefore, the study of the eigenvalues and eigenvectors of the scattering matrix in the complex frequency plane appears extremely powerful to analyze such systems and derive the critical coupling condition. The latter consists in exactly compensating the leakage of the structure by using the intrinsic losses. Two simple structures, the thicknesses of which are 88 times and 40 times smaller than the perfectly absorbed wavelengths, are presented for reflexion and transmission problems, respectively.
Are nano-fibers an emerging noise control solution?
Authors: Horoshenkov Kirill , Hurrell Alistair , Jiao Mohan
Published: October 2018

This paper presents experimental evidence that laboratory measurements of the acoustical and related non-acoustical data is not a trivial task. This paper also shows that the prediction of the acoustical properties of this seemingly simple material is far from easy. First, there is a problem of characterising the non-acoustical properties of nano-porous membrane with standard laboratory methods. Second, there is a high uncertainty in the value of the membrane thickness which can lead to a substantial change in its predicted acoustical and related non-acoustical properties. Thirdly, there is an argument whether or not sound propagation in a nano-porous membrane can actually be treated as that in a classical porous media. The paper attempts to respond to these questions and to present new evidence that we may not know well yet the true acoustical properties of these fibres. Therefore, the key question is Are nano-fibres still an emerging noise control solution?
Are aerogels an emerging noise control solution or it is just beefed up fiber glass?
Authors: Horoshenkov Kirill , Begum Hasina V.
Published: October 2018

Recently, there has been a number of publications which suggested that aerogels can offer high acoustical performance in terms of their ability to absorb or to insulate against sound. It seems that a bulk of these publications report laboratory experiments on the acoustical absorption or transmission loss performance for samples of particular thickness and lateral dimensions. None of these results appear to be rigorously linked to the aerogel's chemistry or micro-structure. This paper attempts to fill in this gap in information by explaining what these materials actually are, why they work acoustically and what is the underpinning physical phenomenon of aerogel. It is shown that the main reason that these materials are used in applications is that they are fire retardant or their elastic modulus is relatively independent of frequency and that they highly hydrophobic. It is also shown that the absorption performance of fibre glass impregnated by aerogel is generally controlled by the fibre diameter of fibreglass and by the density of the composite structure.
A non-negative artificial neural network configuration for noise predictions
Authors: Spies Lucas D. , McBride Sterling , Burdisso Ricardo , Sandu Corina
Published: October 2018

Artificial Neural Networks (ANN) provide an accurate relationship between user-defined inputs and outputs for complex problems. Their basic units are called neurons. The computation that takes place in each neuron is a weighted summation of its inputs. These results are then implemented as an input to an activation or transfer function, which in turn defines the final neuron’s output. The transfer function configuration is very important when defining the final purpose of the ANN. There are many standard activation functions like pure linear, tangent sigmoid, logistic sigmoid, among others. In this study, an ANN capable of predicting tire pavement interaction noise (TPIN) is constructed. Its outputs correspond to sound pressure in narrowband. Thus, the main requirement is that the outputs must be positive. Several neuron transfer functions were investigated for both hidden and output layers. Finally, a customized hybrid linear-sigmoid transfer function was selected. The final ANN configuration is able to capture typical TPIN spectral content within 400 Hz–1600 Hz. In addition, the error is significantly reduced if compared to those obtained after implementing standard transfer functions.
Characterization of laptop computer noise and vibration using nearfield acoustic holography
Authors: Im Seonghun , Ohm Won-Suk , Jang Inman , Park Heoungkil
Published: October 2018

Noise from a laptop computer can be a source of annoyance, especially when the computer is used in a quiet environment for a long period of time. Apart from the fan noise, an equally troublesome noise, often characterized as the “buzz,” is produced by the vibration of the internal electronics components that transmits through the circuit board and eventually manifests itself as sound radiation. Because the buzz is very low in SPL (but loud enough to cause annoyance in a quiet environment), its measurement requires a nearfield technique that is specialized to a low-intensity sound source. In this talk, we discuss the application of nearfield acoustic holography (NAH) for this purpose, and present an acoustic camera system that can measure and visualize the noise and vibration of a laptop computer. The acoustic hologram measured in the nearfield of a laptop computer is utilized to obtain the two-dimensional maps of the acoustic intensity and the velocity of vibration on the surface of the laptop as well as the total radiated power. The NAH-based acoustic camera system described here proves to be an effective tool for characterization and control of noise and vibration present in mobile electronic devices.
Noise exposure assessment of a modular construction manufacturing factory
Authors: Dabirian Sanam , Lee Joonhee , Han Sanghyeok
Published: October 2018

The National Institute for Occupational Safety and Health (NIOSH) has laid down specific regulations to prevent harmful impacts of noise on workers. However, due to the lack of awareness of irreparable noise damages, the potential of the auditory and non-auditory diseases is increasing. In the modular construction manufacturing, which is increasingly applied as a construction method, construction workers are substantially exposed to high-noise levels. In order to provide a healthier workplace, assessment of the noise exposure is necessary while in this industry has not been fully studied yet. Therefore, this paper presents noise exposure assessment of a modular construction factory. After investigating patterns of the tasks, task-based method (TBM) was applied as a measurement strategy. K-means clustering was used to determine the noise level of each task to calculate the noise exposure levels in different locations of the factory. The results of this paper can provide a useful guideline to manage the noise efficiently in the modular construction sector.
Spherical harmonic formulations for passive and active control of acoustic scattering around the sphere
Authors: Orita Mihai , Elliott Stephen , Cheer Jordan
Published: October 2018

Acoustic cloaking can be implemented using different strategies: passive, active, or a combination of both. The literature on this topic is rich when it comes to the passive methods, specifically on metamaterial designs. However, active and hybrid methods are less well explored. In this work, spherical harmonic decomposition is used to calculate the scattering from a spherical obstacle subjected to an incident, monochromatic plane-wave. Its surface is defined through boundary conditions equivalent to a uniform, locally reacting impedance (Robin condition). Secondary sources represented by point-monopoles on the sphere are used to form an active control system. In the absence of active control, at low-frequencies, the least scattering is achieved if the surface impedance is negative, purely imaginary and has a large absolute value. At high-frequencies, the best performance is realised with a real, positive impedance that is close to that of the exterior propagation medium. When adding active control, only the low-frequency regime shows improvement, given any impedance, and it is most beneficial to enhance for the previous case that exhibited the best passive performance. Thus, a promising hybrid cloaking approach is a combination of: a stiffened-controlled boundary with multi-channel active control at low-frequencies, and a passive, absorptive boundary at high-frequencies.
Immersive experimentation: A new paradigm for low-frequency acoustic and elastic wave propagation experimentation
Authors: van Manen Dirk-Jan , Becker Theodor S. , Börsing Nele , Thomsen Henrik R. , Moleron Miguel , Robertsson Johan O.
Published: October 2018

Immersive experimentation is a new paradigm for wave-based laboratory experimentation aimed at overcoming the laboratory- and sample-size related limitations of conventional approaches and thereby significantly extending downwards the usable frequency range. Using so-called immersive boundary conditions, a physical experimentation domain or elastic rock volume can be immersed in an arbitrary larger numerical domain in such a way that the waves in the physical domain drive the simulation in the numerical domain and vice-versa. Waves propagating towards the edges of the experimentation domain are sensed by dense receiver arrays and extrapolated to/ decomposed at the boundary where they are actively suppressed. Waves incident on the boundary are also extrapolated through the larger numerical domain using pre-computed Green’s functions and re-emitted into the experimentation domain, enabling arbitrary order scattering interactions between the laboratory or sample and the numerical domain. We present two laboratories currently under construction at ETH Zurich: WaveLab, an acoustic lab, which implements immersive experimentation in real-time using a low-latency, high-performance acquisition, compute and control system and matrix, an elastic experiment, which implements immersive experimentation using a robotized three-component scanning LDV and novel methods for wavefield separation and injection at an elastic free surface. Implementation, results, and applications are discussed.
Numerical simulations of acoustic cloaking in a real laboratory that deploys immersive boundary conditions
Authors: Börsing Nele , Becker Theodor S. , Curtis Andrew , van Manen Dirk-Jan , Haag Thomas , Bärlocher Christoph , Robertsson Johan O.
Published: October 2018

Immersive boundary conditions (IBCs) act as a wavefield injection method that couples a physical wave propagation experiment to an arbitrary virtual domain. They allow novel, real-time applications for acoustic wave experimentation such as interactions between physical and virtual domains, broadband cloaking, and holography. The implementation of IBCs relies on actively injecting a particular wavefield on the boundary of the physical domain from a dense array of transducers. The injected wavefield must honour the real-world physical and the virtual or computational domains. To calculate the required inputs, a dense array of recording transducers inside the boundary is used from which the future wavefield arriving at the source transducers can be predicted using a discretised Kirchhoff-Helmholtz integral. Whereas IBCs are effectively exact for purely numerical applications, a physical implementation in a laboratory suffers from limitations mainly associated with spatial and temporal discretization issues and the imprint of the electrical devices such as transfer functions or radiation characteristics of transducers. We present a comprehensive numerical sensitivity study of a cloaking experiment in a 2D acoustic waveguide. This defines physical limitations of real-world IBCs, and systematic errors introduced due to subsampling of the recording and injection surfaces and to radiation characteristics of the transducers.
Physical implementation of immersive boundary conditions in acoustic waveguides
Authors: Becker Theodor S. , Börsing Nele , van Manen Dirk-Jan , Haag Thomas , Bärlocher Christoph , Robertsson Johan O.
Published: October 2018

The physical implementation of so-called immersive boundary conditions (IBCs) allows the construction of anechoic chambers, where wavefield reflections from the boundary of a physical domain, such as a wave propagation laboratory, are actively suppressed by emitting a secondary wavefield at the domain boundary that destructively interferes with the reflected waves. Moreover, IBCs enable immersive wave propagation experimentation by linking the wave propagation in the physical domain with the propagation in a numerical domain enclosing the physical domain. In this case, IBCs correctly account for all wavefield interactions between both domains, including higher-order scattering. The physical implementation of IBCs is achieved by densely populating the boundary surrounding the physical domain with transducers that enforce the necessary boundary conditions. The signals required at the injection boundary are predicted with the help of a secondary surface of transducers that record the wavefield on a surface slightly inside the physical domain. The recorded wavefield is extrapolated to the boundary by evaluating a Kirchhoff-Helmholtz integral in real-time using an FPGA-enabled data acquisition, computation and control system. Here, we present results of the active suppression of broadband boundary reflections in 1D and 2D acoustic waveguides.
Finding the beat: An ethnographic approach to beat perception
Authors: Khalil Alexander K.
Published: October 2018

People commonly use words such as “find,” “hold,” “keep,” and “drop” to describe actions related to the musical beat. While such language implies that musical beats exist in an empirically observable, externalized way, musical beats exist only in our perception. This is most clearly evident when people of different cultures perceive different musical beats while listening to the same musical stimuli. At an early age, the ability to discriminate rhythms uncommon to one's surrounding culture declines steeply. However, it has also been shown that rhythmic training may slow or even reverse this decline. This paper explores this process from an ethnographic perspective, observing the way in which American schoolchildren engage with the different temporal dynamics and aesthetics they encounter as they participate in a multicultural music program across several inner-city schools in Southern California.
Extended high-frequency hearing enables better talker and singer head orientation detection
Authors: Monson Brian B.
Published: October 2018

Why is the human auditory brain endowed with sensitivity to acoustical energy at frequencies beyond 8 kHz? While this “treble” range is known to be important for music quality, we hypothesize that extended high-frequency hearing capability has been obtained and retained, in part, due to its utility for the detection and perception of conspecific vocalizations (i.e., human speech and voice). More specifically, we hypothesized that access to the highest frequencies enables better detection of a vocalizer’s head orientation. To test this hypothesis, we assessed human listeners’ ability to detect changes in talker and singer head orientations, and the effect of removing access to the highest frequencies on that ability. Detection of head orientation was significantly impaired by low-pass filtering at 8 and even 10 kHz. One implication is that extended high-frequency hearing loss might impair a listener’s ability to detect whether a talker is facing the listener—a skill presumably useful for “cocktail party” listening.
Vibration suppressions using a dynamic absorber embedded with acoustic black hole features
Authors: Zhou Tong , Cheng Li
Published: October 2018

By capitalizing on the acoustic black hole (ABH) phenomena, an ABH-featured vibration absorber is proposed for the broadband vibration suppressions of a primary structure. As an add-on device to be attached to the primary structure, the proposed absorber embraces the principles of both dynamic vibration absorbers and waveguide absorbers. Its design and implementation avoids the tedious parameter tuning, thus showing robustness to accommodate structural variations in the primary structure. Using a beam as a benchmark example, both numerical simulations and experiments show that multiple resonances of the primary structure can be significantly reduced, and the same absorber can be used for different primary systems. Analyses reveal the existence of three types of vibration reduction mechanisms, manifested differently and dominated by different physical process, i.e.,structural interaction, damping enhancement, and their combination. Comparisons with a conventional uniform beam absorber shows that the superiority of the proposed absorber is attributed to its ABH-specific features exemplified by the enriched system dynamics and the enhanced broadband damping.
Acoustic carpet cloaks based on anomalous reflectors
Authors: Martí-Sabaté Marc , Jin Yabin , Torrent Daniel
Published: October 2018

We present an acoustic carpet cloak based on acoustic anomalous reflectors. The cloak consists on a engineered diffraction grating, designed in such a way that a wave incident with a given angle is “retrorefflected,” so that a pyramidal surface reflects a normally incident wave as if it were a flat surface. Different geometries and angles of the surface are tested, showing that the surface can have an arbitrary shape, as long as the retrorreflection conditions be satisfied locally. Finally, the experimental characterization of these cloaks is discussed.
Relationship between intraglottal geometry, vocal tract constriction, and glottal flow during phonation of a canine larynx
Authors: Farbos de Luzan Charles , Khosla Sid M. , Oren Liran , Maddox Alexandra , Gutmark Ephraim
Published: October 2018

Hypothesis: The rapid reduction of the glottal volume flow rate, which usually occurs in normal phonation during the closing of the vocal folds, is measured by a quantity known as the maximum flow declination rate (MFDR). Our preliminary work highly suggests that intraglottal flow separation vortices (FSV), which form near the superior aspect of the divergent folds during closing, can directly affect MFDR. In this project, we hypothesize that the strength of the vortices is highly correlated with higher MFDR, larger divergence angles and stronger FSV. Methodology: We use particle image velocimetry to measure the strength of the FSV as well as the intraglottal pressures during phonation in four excised canine larynges with an attached mechanical vocal tract. Two vocal tract models are used, one with a false fold gap of 7 mm, one with a gap of 3 mm. Results: Stronger FSV (measured by vorticity) are correlated with glottic efficiency, larger glottal divergence angles and/or with decreased distance between the false folds. Conclusion: We show correlation of the strength of the FSV with different variables. These data are currently being used to validate computational flow structure models. These computational models then can be used to determine causation.
Bi-directional equalization for long-range underwater acoustic communication in East Sea of Korea
Authors: Kim Hyeonsu , Kim Sunhyo , Choi Jee Woong , Bae Ho Seuk
Published: October 2018

The long-range underwater acoustic communications using a sound channel in deep sea have been studied for many years. The acoustic waves transmitted through the sound channel can be propagated by long distance because there is no interaction with the sea surface and bottom interfaces. However, the transmitted signals are distorted by multipath propagation. Time reversal combining followed by a single channel equalizer can reduce efficiently the effects of multipath communication channel and thus increases signal-to-noise ratio by obtaining temporal and spatial diversity. However, the conventional time reversal tends to increase the entire error rate when burst errors occur. Long-range communication signals are particularly vulnerable to burst errors due to the weak signal strength. In this talk, the bi-directional equalization is applied to compensate for the distortion of long-range communication signals where the burst errors occur. Since the bi-directional equalization combines the soft outputs of forward and backward equalization, the effect of error propagation due to burst error can be reduced. The long-range communication experiment data acquired in the East Sea of Korea in October 1999 is used to verify the performance of the bi-directional equalization. The results show that the bi-directional equalization can be effectively applied when burst errors exist. [Work supported by the ADD(UD170022DD) and the National Research Foundation of Korea (NRF-2016R1D1A1B03930983).]
Identifying trends in worship space acoustics: 3 decades of design
Authors: Ahrens Stephanie A. , Ryherd Erica E. , Ronsse Lauren M. , Bradley David T.
Published: October 2018

Worship Space Acoustics: 3 Decades of Design—published by the Acoustical Society of America in 2016—is a book rich with detailed acoustic and architectural information for 67 worship venues with diverse acoustic designs. The venues represent a range of worship space types, various geographic locations around the globe, an assortment of architectural typologies, and a variety of sizes (including seating capacities ranging from 100 to 21,000). This project aimed to synthesize the acoustic and written content presented in the book in order to identify design trends across the 67 venues. Qualitative data included venue typology, location of materials, sound system design, floor plate and room shape, intended use of space, and noise sources, which were mined and analyzed using text analytics software. Quantitative data included reverberation time, background noise level, seating capacity, and room volume. By compiling the various qualitative and quantitative data across all venues, acoustic data and design strategies were synthesized to illustrate popular trends in worship space acoustic design over the last three decades.
The modern sophistication of acoustics in education environments
Authors: Lenz Richard L.
Published: October 2018

In the past 10 years the use of acoustic design and products in educational environments, from elementary schools to universities, has grown exponentially. While acoustics in general has been more widely embraced to solve problems related to modern design technologies, the use of more sophisticated designs and materials has been widely accepted as an alternative to the simple absorptive materials of the past. Some secondary school designs challenge the finest college and university campuses for both creative and effective acoustic spaces. Likewise, some colleges and universities challenge the finest commercial venues, studios and rehearsal spaces in both function and design. Examples will be shown in the presentation including a new convertible acoustic system at Tabor College designed to make the hall usable for both classical performance and sound reinforced, high volume contemporary performances as well. Discussions as to the principals behind the use of acoustics in these environments will be offered.
Flexibility means adaptability: Bats adapt to jamming scenarios better than dolphins
Authors: Kloepper Laura
Published: October 2018

Bats and dolphins both use sonar to image their environment, but frequency modulated (FM) bats demonstrate greater flexibility in echolocation than their marine counterparts, modifying the time-frequency shape of their calls. Bats' FM signals can change depending on foraging phase, environment, or even density and proximity of conspecifics. By changing their time-frequency call structure, bats can acquire different information than by using a stereotyped signal, such as the impulsive signal produced by dolphins. In my talk, I argue that bats have the superior sonar system due to this flexibility. I compare the signals between bats and dolphins and demonstrate new data on how both bats and dolphins adjust echolocation signals in jamming scenarios.
Towards the topology of autoencoder of calls versus clicks of marine mammal
Authors: Roger Vincent , Ferrari Maxence , Marxer Ricard , Chamroukhi Faicel , Glotin Herve
Published: October 2018

The goal is to learn the features and the representation adapted for cetacean sound dynamics without any priors. Thus, we develop data driven model to generate voicing and click of cetaceans audio signals. We learn representation and features of stationary or nonstationary emission using neural network from raw audio. We use different types of convolutions (causal, with strides, with dilation [1]), or gradient inversion [2]. Experiments are conducted on various kind of calls of humpback whales from nips4b challenge [3] or Orca whale. We compare the topology for transient encoding on Physeters and Inia g. For each model, we detail the resulting filters and discuss on the topology. We acknowledge Region PACA and NortekMED for Roger’s Phd grant, & DGA and Région Haut de France for Ferrari’s Phd grant. [1] Oord, Dieleman, Zen, Simonyan, Vinyals, Graves et al. Wavenet : A generative model for raw audio, arXiv:1609.03499, 2016 [2] Balestriero, Roger, Glotin, Baraniuk, Semi-Supervised Learning via New Deep Network Inversion, arXiv:1711.04313, 2017 [3] Glotin, LeCun, Mallat et al. Proc. 1st wkp on Neural Information Processing for Bioacoustics NIPS4B, joint to NIPS Alberta USA, 2013 http://sabiod.org/nips4b/challenge2.html, http://sabiod.org/NIPS4B2013_book.pdf
Target-oriented waveform inversion
Authors: Cui Tianci , Rickett James E. , Vasconcelos Ivan
Published: October 2018

Full-waveform inversion (FWI) has demonstrated increasing success in estimating high-resolution medium parameters, which are obtained by minimizing the difference between synthetic and real data on the acquisition surface. In the standard approach, the whole propagation domain needs to be resolved. This highly nonlinear problem is usually solved via a gradient-based local optimization approach, which can be computationally very expensive. We propose target-oriented FWI utilizing novel redatuming techniques. From surface measurements, Marchenko redatuming retrieves full-waveform up- and downgoing wavefields inside the medium at no significant computational cost. We choose two datum locations inside the medium, one above and one below the target volume. Marchenko-redatumed wavefields at both target-enclosing boundaries consist of in- and outgoing wavefields. The outgoing wavefields are the response of the ingoing wavefields being scattered from the target volume only, without interference from the overburden or underburden. We conduct FWI by finding a target model whose response to the ingoing wavefields fit the outgoing wavefields best. The computational cost of targeted FWI, which involves solving the wave equation in the target volume only, will lead to savings over the traditional full-volume approach. We validate our method numerically on a 2D acoustic model.
Road pavement defect assessment through vibration analysis inside vehicles
Authors: Czyzewski Andrzej , Szczodrak Maciej
Published: October 2018

Miniature accelerometer sensors were used for the evaluation of road surface roughness. The device designed for installation in the vehicles is composed of a GPS receiver and of multi-axis accelerometers. Smartphones with built-in accelerometers were also used. Measurement data were collected through the recording of road trips employing 3 car types on diversified surface roughness roads and with varied vehicle speed on each investigated road section. The first step of data processing was the sensor alignment made to achieve proper values of acceleration vector. Subsequently, the influence of the car suspension system to the measurement results was diminished employing a designed filter. The magnitude of coefficients of Gabor transform analysis of accelerometer signals was calculated to discover differences between good and damaged surface. Research results show that road sections quality can be assessed by the applied vibration analysis. Although the precision of low-cost devices may be lower than the application of expensive professional laser profilograph scanning on road pavements, they can help to increase the effectiveness and the coverage of road surface damage detection, through the monitoring of road surfaces with typical cars instead of special test vehicles only. [Research was subsidized by the Polish National Centre for Research and Development and the General Directorate of Public Roads and Motorways within the Grant No. OT4- 4B/AGH-PG-WSTKT.]
Numerical simulation and machine learning based analysis of the ultrasonic waveform propagating in bone tissue
Authors: Nagatani Yoshiki , Okumura Shigeaki , Wu Shuqiong
Published: October 2018

Since bone has a complex structure, it is difficult to analytically understand the behavior of the ultrasound although it is useful for bone quality diagnosis. Our group, therefore, had been working on simulating ultrasound propagation inside bone models. In this paper, the results of the neural network based bone analysis using waveforms derived by the 3-D elastic FDTD (finite-difference time domain) simulation will be presented as well as its basis and some representative results of the FDTD method applied for the bone assessment. Since the FDTD simulation only requires the 3-D geometry of the model and the acoustic parameters (density, speed of longitudinal wave and shear wave) of the media, it has been very useful for evaluating each effect of a certain acoustic parameter or the bone geometry such as bone density, respectively, in addition to the purpose of visually understanding the wave behavior inside the model including the propagation path. Moreover, thanks to the recent powerful computational resource, it is now realized to prepare a huge number of waveforms for machine learning by using FDTD method. As a result, it was shown that the neural network can estimate the bone density better than the traditional method. (Grant: JSPS KAKENHI 16K01431.)
Physical Activity Promotion for Persons Experiencing Disability: The Importance of Interdisciplinary Research and Practice
Authors: Agiovlasitis Stamatis , Yun Joonkoo , Jin Jooyeon , McCubbin Jeffrey A. , Motl Robert W.
Published: October 2018

This paper examines the need for interdisciplinary knowledge in the formation of public health models for health-promoting physical activity (PA) for people experiencing disability. PA promotion for people experiencing disability is a multifaceted endeavor and requires navigating a multitude of complicated and interactive factors. Both disability and health are multifaceted constructs and the relationship between PA and health is embedded within a complicated web of interactive influences. PA promotion must consider interacting biological and psychosocial factors within the person and in the sociopolitical environment. Models for research and practice need to evolve from value and belief systems that center on people experiencing disability without stigmatizing them. We argue that interdisciplinary research and practice is needed in navigating the intricacies of PA promotion toward improving the health of people experiencing disability and facilitating inclusion, empowerment, and dignity.
Understanding Correlates of Physical Activity in American Indian Families: The Healthy Children Strong Families-2 Study
Authors: Grant Vernon M. , Tomayko Emily J. , Prince Ronald J. , Cronin Kate , Adams Alexandra
Published: October 2018

Background: Little is known about factors contributing to physical activity (PA) in American Indian (AI) populations. Addressing this gap is paramount as sedentary activity and obesity continue to increase in this population. The purpose of this study was to determine factors associated with PA among AI families with young children.Methods: Height and weight of both adult (n = 423) and child (n = 390) were measured, and surveys assessed demographics, PA, stress (adult only), sleep, and screen time. Separate multivariate logistic regression models were constructed for adults and children (reported as adjusted odds ratios, aORs).Results: For adults, age (aOR = 0.952;P ≤ .001), television viewing (aOR = 0.997;P = .01), and computer use (aOR = 0.996;P = .003) decreased the odds of being active. For children, high adult activity (aOR = 1.795;P ≤ .01), longer weekday sleep (aOR = 1.004;P = .01), and family income >$35,000 (aOR = 2.772;P = .01) increased the odds of being active. We found no association between adult PA with stress or adult sleep or between child PA with body mass index and screen time.Conclusions: Given the complexity of the factors contributing to obesity among AI families, multigenerational interventions focused on healthy lifestyle change such as decreasing adult screen time and increasing child sleep time may be needed to increase PA within AI families.
Umbrella and Systematic Review Methodology to Support the 2018 Physical Activity Guidelines Advisory Committee
Authors: Torres Andrea , Tennant Bethany , Ribeiro-Lucas Isabela , Vaux-Bjerke Alison , Piercy Katrina , Bloodgood Bonny
Published: October 2018

Introduction: In 2016, the 2018 Physical Activity Guidelines Advisory Committee, a group of experts in exercise science and health, began an extensive review of the literature to inform the second edition of the Physical Activity Guidelines for Americans. Methods: The purpose of this paper is to describe the evidence-based methodology used to review, evaluate, and synthesize published, peer-reviewed physical activity research. The protocol-driven methodology was designed to maximize transparency, minimize bias, and ensure relevant, timely, and high-quality systematic reviews. Training protocols, quality control procedures, search strategies, assessment instruments, abstraction guides and forms, and reporting templates were developed. Results: A systematic approach was used to select the evidence for the 2018 Physical Activity Guidelines Advisory Committee Scientific Report that included umbrella reviews and systematic reviews. Within 16 months, 38 searches were conducted; and 20,838 titles, 4913 abstracts, and 2139 full texts were triaged. Of those, 1130 articles were abstracted to answer 38 research questions. Conclusions: To inform population-based physical activity guidelines, this systematic process facilitated a vast review of the literature on physical activity and health in a short period of time. This flexible, yet rigorous and transparent process included a clear and detailed methodology with a focus on training and quality control.
Functional regeneration of tendons using scaffolds with physical anisotropy engineered via microarchitectural manipulation
Authors: Wang Z. , Lee W. J. , Koh B. T. H. , Hong M. , Wang W. , Lim P. N. , Feng J. , Park L. S. , Kim M. , Thian E. S.
Published: October 2018

Polymer axial drawing enables the design of optimal microarchitectured scaffolds for tendon regeneration.
Somatic mutant clones colonize the human esophagus with age
Authors: Martincorena Iñigo , Fowler Joanna C. , Wabik Agnieszka , Lawson Andrew R. J. , Abascal Federico , Hall Michael W. J. , Cagan Alex , Murai Kasumi , Mahbubani Krishnaa , Stratton Michael R. , Fitzgerald Rebecca C. , Handford Penny A. , Campbell Peter J. , Saeb-Parsy Kourosh , Jones Philip H.
Published: October 2018

The mutational burden of aging

As people age, they accumulate somatic mutations in healthy cells. About 25% of cells in normal, sun-exposed skin harbor cancer driver mutations. What about tissues not exposed to powerful mutagens like ultraviolet light? Martincorenaet al.performed targeted gene sequencing of normal esophageal epithelium from nine human donors of varying age (see the Perspective by Chanock). The mutation rate was lower in esophagus than in skin, but there was a strong positive selection of clones carrying mutations in 14 cancer-associated genes. By middle age, more than half of the esophageal epithelium was colonized by mutant clones. Interestingly, mutations in the cancer driver geneNOTCH1were more common in normal esophageal epithelium than in esophageal cancer.

Science, this issue p.911; see also p.893
Serologic Response to Cell Wall Mannoproteins and Proteins ofCandida albicans
Authors: Martínez José P. , Gil M. Luisa , López-Ribot José L. , Chaffin W. LaJean
Published: October 2018

The cell wall of Candida albicans not only is the structure in which many biological functions essential for the fungal cells reside but also is a significant source of candidal antigens. The major cell wall components that elicit a response from the host immune system are proteins and glycoproteins, the latter being predominantly mannoproteins. Both the carbohydrate and protein moieties are able to trigger immune responses. Although cell-mediated immunity is often considered to be the most important line of defense against candidiasis, cell wall protein and glycoprotein components also elicit a potent humoral response from the host that may include some protective antibodies. Proteins and glycoproteins exposed at the most external layers of the wall structure are involved in several types of interactions of fungal cells with the exocellular environment. Thus, coating of fungal cells with host antibodies has the potential to influence profoundly the host-parasite interaction by affecting antibody-mediated functions such as opsonin-enhanced phagocytosis and blocking the binding activity of fungal adhesins for host ligands. In this review, the various members of the protein and glycoprotein fraction of the C. albicans cell wall that elicit an antibody response in vivo are examined. Although a number of proteins have been shown to stimulate an antibody response, for some of these species the response is not universal. On the other hand, some of the studies demonstrate that certain cell wall antigens and anti-cell wall antibodies may be the basis for developing specific and sensitive serologic tests for the diagnosis of candidasis, particularly the disseminated form. In addition, recent studies have focused on the potential for antibodies to cell wall protein determinants to protect the host against infection. Hence, a better understanding of the humoral response to cell wall antigens of C. albicans may provide the basis for the development of (i) effective procedures for the serodiagnosis of disseminated candidiasis and (ii) novel prophylactic (vaccination) and therapeutic strategies for the management of this type of infection.
Molecular Typing of Enteroviruses: Current Status and Future Requirements
Authors: Muir Peter , Kämmerer Ulrike , Korn Klaus , Mulders Mick N. , Pöyry Tuija , Weissbrich Benedikt , Kandolf Reinhard , Cleator Graham M. , van Loon Anton M.
Published: October 2018

Human enteroviruses have traditionally been typed according to neutralization serotype. This procedure is limited by the difficulty in culturing some enteroviruses, the availability of antisera for serotyping, and the cost and technical complexity of serotyping procedures. Furthermore, the impact of information derived from enterovirus serotyping is generally perceived to be low. Enteroviruses are now increasingly being detected by PCR rather than by culture. Classical typing methods will therefore no longer be possible in most instances. An alternative means of enterovirus typing, employing PCR in conjunction with molecular genetic techniques such as nucleotide sequencing or nucleic acid hybridization, would complement molecular diagnosis, may overcome some of the problems associated with serotyping, and would provide additional information regarding the epidemiology and biological properties of enteroviruses. We argue the case for developing a molecular typing system, discuss the genetic basis of such a system, review the literature describing attempts to identify or classify enteroviruses by molecular methods, and suggest ways in which the goal of molecular typing may be realized.
Gene Therapy for Infectious Diseases
Authors: Bunnell Bruce A. , Morgan Richard A.
Published: October 2018

Gene therapy is being investigated as an alternative treatment for a wide range of infectious diseases that are not amenable to standard clinical management. Approaches to gene therapy for infectious diseases can be divided into three broad categories: (i) gene therapies based on nucleic acid moieties, including antisense DNA or RNA, RNA decoys, and catalytic RNA moieties (ribozymes); (ii) protein approaches such as transdominant negative proteins and single-chain antibodies; and (iii) immunotherapeutic approaches involving genetic vaccines or pathogen-specific lymphocytes. It is further possible that combinations of the aforementioned approaches will be used simultaneously to inhibit multiple stages of the life cycle of the infectious agent.