bluuebunny/crossref_metadata_2025 huggingface dataset:
The contribution of research platforms to the pathway from off-line to real-time high-frame-rate imaging
Authors: Tortoli Piero , Boni Enrico
Published: November 2019

Ultrasound research platforms are characterized by a great flexibility of parameters that are usually fixed on clinical scanners. They allow the transmission of arbitrary waveforms in arbitrary scan sequences, and to test novel methods by processing off-line the raw radiofrequency channel data received after each transmission (TX) event. In particular, the availability of research platforms has boosted the development of high-frame-rate (HFR) imaging methods. These are typically based on the TX of multi-line focused beams, plane waves or diverging waves, which can be optimally produced by linear power amplifiers. The echoes received after each TX event should thus be beamformed along multiple lines in parallel, which is feasible, on line, only when high processing power is available. In this talk, the characteristics of “hardware-based” research platforms, like the ULA-OP 256, are discussed. The presence of powerful FPGA devices, on board such systems, allows implementing efficient parallel beamforming methods, which is the key-requirement for HFR imaging. Sample results obtained in real-time at rates of hundreds frames/s will be presented for both multi-line and plane wave compounding scan sequences. Finally, the main challenges to be faced to extend such modalities to volumetric (3-D) imaging will be discussed.
Vector flow imaging using a deep neural network
Authors: Li You L. , Ducey-Wysling Jessica , D’Hondt Aurélie , Hyun Dongwoon , Patel Bhavik , Dahl Jeremy J.
Published: November 2019

Vector flow imaging (VFI) estimates blood flow velocities in both azimuth and axial dimensions. VFI has promising applications in the characterization of complex flow patterns, including cardiac flow and abdominal flow imaging. Conventional VFI relies on the use of multiple angles in transmit or receive, or speckle tracking. They are computationally intensive and estimate quality may be sacrificed to improve computational speed. In this work, we report a vector flow estimation technique using a deep neural network. The network extracts feature from high-pass filtered beamsummed RF data of two consecutive Doppler packets. For each packet, the RF data have azimuth and axial dimensions. It then performs estimation of vector flow in the feature space, and maps the estimate back to the spatial domain. The total computation time is 0.11 s for a pair of Doppler frames of 1024 × 128 samples. The performance of the method is characterized using Field II simulation studies, flow phantom studies, and an in vivo liver study with a Verasonics Vantage 256 scanner. The simulation and flow phantom studies show good agreement between the estimates and the ground truth. The in vivo studies demonstrate that the method is capable of characterizing complex flow patterns in human liver vessels.
Using the Doppler effect to characterize microbubble shell viscoelasticity
Authors: Supponen Outi , Guidi Francesco , Upadhyay Awaneesh , Vos Hendrik J. , Tortoli Piero , Borden Mark
Published: November 2019

The experimental testing and quality control of microbubble formulations for ultrasound applications requires high-throughput measurement of physicochemical properties, such as shell elasticity and viscosity. Single-bubble optical experiments are slow and expensive. Ultrasound attenuation experiments on microbubble populations can be done quickly, but the measurement is averaged over the ensemble, and it is often difficult to separate effects of microbubble size from shell viscoelasticity. Here, we discuss a relatively simple alternative method of using the Doppler effect to measure ultrasound radiation force-induced displacements of many individual microbubbles within a population. Our method involves insonifying a diluted suspension of freely floating microbubbles with a linear-array ultrasound probe driven by an open scanner. The microbubble displacements along the axis of the insonified region were acquired from the frequency shifts in the measured echo signals using the multi-gate spectral Doppler approach. These measurements were compared with theoretical peak microbubble displacements computed by combining a modified Rayleigh-Plesset equation and a balance of translational forces. The shell elasticity and viscosity producing the measured peak microbubble displacement was determined by assuming a resonant bubble size at each driving frequency. Our initial results are encouraging, and demonstrate a step toward high-throughput microbubble characterization using the Doppler effect.
Reduced order modeling of interior noise for an aircraft during early stage design
Authors: Vlahopoulos Nickolas , Zhang Geng
Published: November 2019

The design of an aircraft must balance the performance in many disciplines in order to achieve performance expectations at minimum weight and cost. During the conceptual design phase there is no time for developing detailed simulation models and decisions are typically made either by using low fidelity models or existing data and regression models. However, the decisions made during the conceptual design phase greatly affect the performance of the aircraft and the associated cost. The structural design during early product development focuses on strength, fatigue, corrosion, maintenance, inspection, and manufacturing. The structures are designed as a load carrying shell reinforced by frames and longitudinals, and a skin-stringer construction supported by spars and stiffeners. The structural design of the fuselage is directly related with the interior noise performance of the aircraft. Therefore, an easy to use, computational, physics based capability for interior noise prediction, which requires small computational resources, and can operate using the same amount of limited data which is available for the structure during the early product development stages, is a key enabler in bringing interior noise computations in early aircraft design. A case study of such capability will be presented.
Applying a numerical Green's function approach to scattering within complex seafloor environments
Authors: Gunderson Aaron
Published: November 2019

A numerical approach to solving for Green’s functions allows far-field scattering to be solved within variable seafloor environments. The approach is applicable for both seafloor and buried target scattering problems. A robust near-field model is required for near-field solution evaluation and Green’s function determination. In this work, a 3-D finite element model is used. Far-field scattering results are determined through numerical integration of the Helmholtz-Kirchhoff surface integral within the near-field of the target or interface. This approach has previously been shown to give accurate results within flat sediment interface environments; now the technique is extended to more complex interface structures, in which the benefit of the numerical Green’s function technique is most apparent. For flat interface environments, analytic Green’s functions are known, making numerical approaches redundant. For more complex environments, exact solutions are difficult to come by, and analytic approximations grow in error with increasing environmental complexity. Furthermore, the numerical approach requires only a single field measurement to be made within the near-field model, making the approach computationally efficient and feasible for a wide variety of scattering problems. [Work supported by ONR, Ocean Acoustics.]
Decolonizing African music with visualizations and sonifications using beat-class theory
Authors: Calilhanna Andrea , Onwubiko Stephen G.
Published: November 2019

In a recent paper, we introduced mathematical music theory as a suitable new approach to analyze the music of Nigeria (Igbo) (Calilhanna et al., 2019). This paper revisits those materials and extends the ideas to further discuss why Nigerian music can be studied more suitably using mathematical music theory. We address a key issue facing music curriculum development: the perpetuation of traditional Western music theory to analyze and understand all music around the world. Our paper aims to demonstrate how Western music theory is inadequate for analyzing Nigerian music and we present some ways Western music theory has evolved. We explain how new music theory combines understandings of both music and mathematics and with a focus on musical meter we present a student-centred approach to learning. We achieve this through visualizations and sonifications of beat-class theory, using ski-hill graphs and circular cyclic graphs. This approach enables the listener to accurately articulate their subjective embodied psychoacoustic experience of music, meter and mathematics and incorporates research in neuroscience, music education, music psychology and music acoustics, which consistently indicates the importance of music for the well-being of the individual, school, workplace, and community.
Acoustic correlates of talker height in children’s voices
Authors: Thomas Abbey L. , Barreda Santiago , Assmann Peter F.
Published: November 2019

In a recent study, we investigated listeners’ ability to judge talker height from CVC syllables spoken by children. The present study extends this research by examining acoustic variables that predict talker height. We analyzed recordings of the sustained vowel /a/ produced by children 5 through 18 years of age, taken from a larger children's speech database. In addition to measures previously found to predict speaker height (GMFF and G0, the geometric mean of the lowest three formant frequencies and fundamental frequency, respectively) we investigated measures related to the glottal source reflecting breathiness and spectral tilt. Multiple regression models incorporating these measures provided accurate estimates of talker height (mean average error of 9.3 cm). Consistent with our previous findings for age, a model specifying the sex of the talker predicts talker height significantly more accurately than a model that excludes sex.
A convolutional neural network applied to measured time series for source range and ocean seabed classification
Authors: Van Komen David F. , Neilsen Tracianne B. , Knobles David P. , Dahl Peter H. , Dall'Osto David R.
Published: November 2019

Source localization and environmental inference are common problems in ocean acoustics requiring computationally intensive algorithms and knowledge of the search space. Convolutional neural networks (CNNs) learn useful features for making predictions directly from a gridded input signal circumventing the costly practice of selecting features or comparisons to a forward propagation model. To take advantage of these benefits, a CNN was trained and validated on simulated pressure signals generated using four different environments (sandy, muddy, and mixed-sediment layers) for several ranges (2 to 12 km) to make environment class and range predictions. The trained network was then tested on recorded signals from the APL-UW Intensity Vector Autonomous Receiver system during SBC2017. We found that the network could make predictions with 99% accuracy on the simulated validation dataset but struggled to make unbiased predictions on the measured data. The struggles highlight the need to incorporate all significant features in the training data, such as time alignment and addition of noise. The CNN has the power to make predictions on this type and clearly see the differences in the data, but investigations for creating the proper training dataset or building a deeper network are required. [Work supported from Office of Naval Research.]
Audiovisual system design and content creation for immersive virtual environments with deployable panoramic display
Authors: Huang Mincong , Chabot Samuel , Wetzel Joseph , Goebel Johannes , Su Hui , Braasch Jonas
Published: November 2019

State-of-the-art schemata of immersive audiovisual system design mostly rely on in-situ stand-up construction with footings and rigid structural supports, an approach limited by low mobility and long set-up time. In this work, a new concept of audiovisual system design for a collaborative Immersive Virtual Environment with flexible and deployable projection elements and modular assemblies, is proposed. Drawing on stand-up configuration from Rensselaer’s Collaborative-Research Augmented Immersive Virtual Environment Laboratory (CRAIVE-Lab), a foundationless rectangular panoramic display with round corners is used, incorporating a motorized roll-up framework with mountable fillets. This set-up is then accompanied by a unitized 60-channel Wave Field Synthesis (WFS) linear loudspeaker array. The proposed audiovisual system calibrates the spatial audiovisual rendering by an integrated use of game-engine-based 3-D virtual environments (made in Unity and Unreal) and Max/MSP-based sonification utilities. In particular, an equirectangular transform is applied in virtual cameras and render textures to remove distortion effects from screen geometry. This transform is shared with the WFS array for a congruent presentation of audiovisual content.
Acoustic manifestations of “narrow focus” in Apurímac Quechua vowels
Authors: Alkahtani Faisal
Published: November 2019

This paper investigates the acoustic manifestations of “narrow focus” on the vowels of Apurímac Quechua. Specifically, the three acoustic correlates of duration, intensity, and mean F0 in the vowels of stressed syllables were measured to see how narrow focusis expressed and if it would have a significant enhancing effect on the target vowels /a/, /i/, and /u/. 180 tokens were used in this experimental study, 90 in “focus” condition and 90 in “non-focus” condition (30 for each vowel in both conditions). Paired t-tests were conducted for each correlate, and the results show that duration is significantly longer (p < 0.01) in focus condition (mean = 47.22 ms, SD = 10.84) compared to non-focus condition (mean = 47.22 ms, SD = 10.84). The same pattern is found for intensity where vowels in focus condition (mean = 66.44 dB, SD = 4.85) were a significantly louder (p < 0.01) than the vowel in non-focus condition (mean = 63.02, SD = 5.27). Finally, the mean F0 for vowels in focus condition (mean = 135.41 Hz, SD = 16.45) was significantly higher (p < 0.01) than the non-focus condition (mean = 117.41). While all correlates show significant increase as a result of being in a focus condition, the duration correlate did not cross the “Just Noticeable Difference” (JND) threshold of 10 ms. On the other hand, intensity and F0 crossed the JND of 3 dB and 1 Hz, respectively. These findings suggest that Apurímac Quechua is a syllable-timed language that does not rely on duration as a primary acoustic correlate of “narrow focus.”
Partial field decomposition of the simulated noise from a highly heated laboratory-scale jet
Authors: Leete Kevin M. , Gee Kent L. , Liu Junhui , Wall Alan T.
Published: November 2019

The decomposition of jet noise fields into self-coherent and mutually incoherent parts is an important step preliminary to the application of acoustical holography techniques. Cross-spectral matrices of point arrays sampled from large eddy simulations of a laboratory-scale jet operating at a high temperature ratio are decomposed using a singular value decomposition to obtain partial fields. The shape and relative strengths of the individual partial fields highlight the difference between the coherent radiation in the aft direction and the incoherent portion of the radiation towards the sideline. Azimuthally, levels are mostly constant but require multiple partial fields to accurately represent the low coherence at high frequency.
Judgments of American male talkers who are perceived to sound gay or heterosexual: Certain social contexts don’t affect perception of personality traits
Authors: Tracy Erik C.
Published: November 2019

Researchers proposed that different social contexts influence how listeners perceive talkers’ emotional states (Bachorowski and Owren, 2002). Furthermore, it was discovered that, in the absence of any context (i.e., listeners were not informed of talkers’ sexual orientation), some personality traits (e.g., confident, mad, stuck-up, and outgoing) were associated with gay-sounding male talkers, while other personality traits (e.g., boring, old, and sad) were associated with heterosexual-sounding male talkers (Tracy, 2016). The first experiment examined whether a stronger association between these traits and voices might emerge if listeners were informed of the talkers’ sexual orientation (i.e., greater social context). After hearing a spoken utterance, listeners rated gay-sounding and heterosexual-sounding talkers along the previously mentioned personality traits. For the majority of traits, the results demonstrated that listeners’ personality judgments did not change if they were told or were not told the sexual orientation of the talker. The second experiment revealed that, in the absence of vocal information, participants do not associate these personality traits with these particular talkers. Thus, the data from the two studies align. If listeners have knowledge of a talker’s sexual orientation, they do not associate this knowledge with particular personality traits and, thus, their personality judgments of the voices would not be affected.
Recursive least squares calibration and tomographic imaging with an ultrasonic transducer array
Authors: Adams Robert W. , Thiel Tim , Harrist Jonathan , Deffenbaugh Max
Published: November 2019

Travel time measurements from an acoustic array interrogating a fluid within the cross-section of a pipe include systematic errors: from mispositioning of array elements, group delays from the transceiver circuits at each element, and acoustic propagation effects between transmitter/receiver pairs. An enhanced calibration model is described which includes the influence of these error sources, and a recursive least squares solution is applied to find calibration travel-time corrections that minimize systematic errors. This enhanced calibration model is applied in-situ to an acoustic transducer array, resulting in increased accuracy and precision of acoustic travel-time measurements. Tomographic images of fluid velocities are derived from these travel-time measurements. The fluid velocities are mapped to known velocities of individual fluid phases, resulting in tomographic images of multiphase flows.
Reproduction and analysis of near and far stereophonic sound fields with compact uniform linear arrays
Authors: Patros Elliot , Afghah Tahereh , Otto Peter
Published: November 2019

Stereo speakers are commonly used for multi-modal listening. This includes both near field, on-axis or "sweet-spot" listening; as well as far field, off-axis or "room-fill" listening modes. Meanwhile, compact uniform linear arrays (cULA) are increasingly available as an alternative to conventional stereo systems. However, acoustic properties of cULA limit their ability to reproduce accurate sound fields for both modes simultaneously. This paper proposes several modifications to wave field synthesis that serve together as a simple and robust method for multi-modal stereo reproduction with cULA. Near field performance is analyzed by comparing estimates of stereophonic localization for both the proposed system and conventional stereo. Far field performance is analyzed by comparing magnitude responses across both systems' sound fields. Finally, connections between array configuration parameters and stereophonic reproduction artifacts are highlighted.
Source level predictions of surface ships using seabed characterization in the New England Mudpatch from viscous grain shearing model
Authors: Knobles David P. , Wilson Preston S. , Hodgkiss William S. , Buckingham Michael J. , Neilsen Tracianne B. , Wan Lin , Badiey Mohsen
Published: November 2019

Acoustic inferences from remote sensing of surface ship radiated noise in bottom-limited ocean environments are difficult due to a generally unknown geoacoustic structure of the seabed. The idea here is to first calibrate an acoustic sensing system by estimating geoacoustic parameter values by utilizing controlled sources with known levels. Then, the acoustic field that results from a surface ship is utilized to estimate the ship source levels where the transmission loss is constructed based on the previous estimate of the seabed parameterization and measurements of the sound speed profile at the time that the ship noise measurements were made. This concept was tested with acoustic data collected on two vertical line arrays (VLAs) during the Seabed Characterization Experiment in the New England Mudpatch during April 2017, in 75 m of water. The acoustic field was produced with a controlled source radiating in the 1.5–4 kHz band. A maximum entropy method provided estimates of viscous grain shearing (VGS) model parameter values. Then, using this VGS parameterization, ship source levels as a function of aspect and frequency out to about 3 kHz were extracted for the RV Endeavor and several merchant ships passing near the VLAs. [Work supported by ONR N00014-16-C-3065.]
Individual horizontal array elements as windows to estimating ship radiated noise signature lobing patterns
Authors: Thomson Dugald , Barclay David R.
Published: November 2019

A horizontal hydrophone array is typically beamformed to produce the directivity required to produce array gain and determine bearing to a contact of interest. For ships passing near an array each omnidirectional hydrophone also provides a number of discrete “look windows” at the ship from a range of received angles. By assembling similar look window angles and applying a propagation model to estimate transmission loss, a partial lobing pattern for the ship's radiated noise signature can be estimated. A 48-element bottom-mounted hydrophone array in the Canadian Arctic provides an opportunity to test this approach in a low ambient noise environment with a variety of passing ships.
Passive acoustic monitoring of ship sounds in Lake Superior
Authors: Putland Rosalyn , Mensinger Allen F.
Published: November 2019

Monitoring freshwater ecosystems using passive acoustics is a largely unexplored approach, despite having the potential to yield information about the biological, geological and anthropogenic activity of a lake or river system. Minnesota, nicknamed “land of 10 000 lakes,” provides an interesting case study, because of the opportunity to compare the soundscape during winter with up to 100% ice cover and no vessel transits, to the open water soundscape during busy summer shipping season. Passive acoustic monitoring was conducted in the coastal waters of the western arm of Lake Superior, close the Duluth port, from October 2018 to September 2019. By combining long-term acoustic monitoring data with AIS vessel-tracking data and acoustic propagation modelling (bathymetry, sound speed profiles and seafloor properties) a quantitative method for determining the impact of vessel noise on the soundscape has been established. Median broadband sound pressure level (100–12 000 Hz) was significantly lower in winter compared to summer. However, during ice free months tankers and cargo vessels played a key role in the daily soundscape increasing the intensity by >30 dB between 300 and 1,000 Hz. Moving forward, baseline sound levels provide vital evidence for scientists and governing bodies to make proactive decisions for soundscape conservation.
“How”: The connection between acoustics and perception
Authors: Stilp Christian
Published: November 2019

Speech is both the most important and the most frequent sound that we hear. We have so much experience perceiving speech that it often seems relatively effortless. However, when one examines the speech signal a bit more closely, several severe challenges are evident such as considerable acoustic complexity and extreme acoustic variability across sounds, utterances, talkers, and environments. Given these challenges, how does speech perception work? In this talk, we will consider how speech sounds are produced and observe some of their prevailing acoustic characteristics in American English. We will then embark on a brief tour of the auditory system. We will see how speech sounds are transduced into action potentials in the cochlea and then how the neural representation of speech evolves as one travels up the central auditory system toward the brain. This tour will conclude with the discussion of speech processing in the brain, including cortical pathways for processing different aspects of the speech signal. Understanding speech acoustics and processing can directly inform efforts to provide speech privacy.
Holographic measurement and simulation of 3-D ultrasound fields distorted by soft-tissue phantoms
Authors: Kreider Wayne , Peek Alex T. , Hunter Christopher , Khokhlova Tatiana D. , Rosnitskiy Pavel B. , Khokhlova Vera A. , Yuldashev Petr V. , Sapozhnikov Oleg
Published: November 2019

Applications of high intensity therapeutic ultrasound (HITU) rely on the accurate delivery of ultrasound to targeted tissues. However, because in situ measurement of 3-D ultrasound fields in tissue is not possible, knowledge of such fields depends upon some form of calculation. Standard approaches utilize measurements in water to characterize the ultrasound source, with fields in tissue estimated by derating or numerical simulation. To evaluate the accuracy of numerical models, simulations and measurements have been performed based on tissue phantoms with known geometries and physical properties. In this work, holography measurements were used to characterize a 256-element HITU transducer in water and to measure directly the 3-D fields behind soft-tissue phantoms designed to introduce refraction, attenuation, and/or aberration. Using synchronization between a waveform digitizer and a computer-controlled positioner, accelerated recording of each hologram (representing over 40 000 points) was performed in about an hour by continuously scanning a capsule hydrophone line-by-line in the measurement plane. Linear measurements are compared with simulations performed using the k-Wave toolbox, and various uncertainties are quantified. It is shown that holography-based modeling accurately represents fields distorted by inhomogeneous layers mimicking body wall. [Funding support by NIH R01-EB025187, R01-EB007643, R01-R01GM122859, and RSF Grant No. 19-12-00148.]
Quantification of lung surface wave speed in a water-filled lung: An ex vivo swine lung study
Authors: Zhang Xiaoming , Zhou Boran , Zhang Alex X.
Published: November 2019

Lung edema is a common symptom of congestive heart failure and inflammatory conditions, such as acute respiratory distress syndrome. Currently, computed tomography (CT) is considered the standard to assess lung edema, but it requires ionizing radiation and poses a significant logistic burden. Lung ultrasound (LUS) has previously been used to assess lung edema using ultrasound B-line artifacts, but analysis of the B-line artifacts relies on visual interpretation. We developed lung ultrasound surface wave elastography (LUSWE) to measure lung surface wave speed safely. This project aims to evaluate LUSWE to quantify lung surface wave speed in an ex vivo water-filled swine lung. The lung surface wave speeds were measured at baseline and at frequencies of 100 Hz, 200 Hz, 300 Hz, and 400 Hz. Then, an amount of water was filled into the lung through its trachea. Ultrasound imaging was used to guide the water filling until significant changes were visible on the imaging. The lung surface wave speeds were measured. An additional 120 ml of water was then filled into the lung. The lung surface wave speeds were measured again. The results demonstrated that the lung surface wave speed decreased with respect to water content.
A closer look at ultrasonic attenuation in a tissue-mimicking material
Authors: Maruvada Subha , Liu Yunbo , Soneson Joshua , Herman Bruce , Harris Gerald
Published: November 2019

A well-characterized ultrasound tissue-mimicking material (TMM) can be important in determining the acoustic output and temperature rise from high intensity therapeutic ultrasound (HITU) devices and also in validating computer simulation models. A HITU TMM previously developed and characterized in our laboratory has been used in our acoustic and temperature measurements as well as modeled in our HITU simulation program. A discrepancy between the thermal measurement and simulation, though, led us to further investigate the TMM properties. We found that the 2-parameter analytic fit commonly used to represent the attenuation of the TMM in the computer modeling was not adequate over the entire frequency range of interest, 1 MHz to 8 MHz in this study, indicating that we and others may have not been characterizing TMMs, and possibly tissue, optimally. By comparing measurements and simulations, we found that a 3-parameter analytic fit for attenuation gave a more accurate value for attenuation at 1 MHz and 2 MHz. When using a 3-parameter fit, the temperature rise measurements in the FDA TMM agreed more closely with the simulation results.
Automatic speech emotion recognition using deep learning for analysis of collaborative group meetings
Authors: Morgan Mallory M. , Bhattacharya Indrani , Radke Rich , Braasch Jonas
Published: November 2019

Emotion is a central component of verbal communication between humans. Due to advances in machine learning and the development of affective computing, automatic emotion recognition is both increasingly possible and increasingly sought-after. In this project, deep learning architectures, such as long short-term memory networks, are used to classify emotion from the prosody of human speech. Emotional groupings are considered both categorically (i.e., happiness, anger, etc.) and with respect to a three-dimensional emotion space divided into axes of valence, activation, and dominance. The network is trained on publicly available emotional speech corpuses and tested on a new dataset as part of a larger project to understand the dynamics of collaborative groupwork. Specifically, small groups were asked to complete a lunar survival task while recorded in a smart meeting room equipped with multimodal sensors. The results of the emotion classification, as well as other non-verbal speech metrics, are correlated with user-reported rankings including emergent group leader and major group contributor, in the hopes of better understanding the complex dynamics of team meetings. [Work supported by NSF IIP-1631674, a Northeastern University Tier 1 Seed Grant, and the Cognitive and Immersive Systems Laboratory (CISL).]
Impact of viscoelastic spheres on to hydrophobic and hydrophilic substrates with liquid pools
Authors: Rabbi Rafsan , Truscott Tadd , Allen John S.
Published: November 2019

The study of the sound of impact has an extensive history with seminal studies done by Rayleigh. Rayleigh studied the subsequent vibrations of an impacting elastic sphere on a solid surface formulating a preliminary, analytical theory for rigid body radiation based on energy considerations. For a spherical particle incident on a non-wetted substrate, the sound pressure level can be related to the particle’s impulsive acceleration. Impact onto wetted substrates is less understood for the cases of hydrophobic surfaces. We investigate the impact of visco-elastic water beads (12.5 mm, 17.5 mm diameter) from heights 35–400 cm upon hydrophilic and hydrophobic liquid pools (0.15–0.45 ml). A hydrophobic surface is obtained by coating the metallic surface of a contact microphone with Soft99 Glaco Mirror Coat Zero water repellant. Sound production is measured using both contact and air microphones, which are synchronized with a high-speed camera (Phantom V2512) for visualization. In the hydrophobic case at low heights, the rebound of the water bead results in the attachment and lift-off of the liquid. The collapse of entrained gas cavities corresponds to an oscillatory acoustic signature upon lift-off. At higher impact heights, the liquid pool is atomized with signatures of drop break-up.
Numerical study on formation of an acoustic soliton in bubbly liquids based on weakly nonlinear wave equation
Authors: Ayukai Takahiro , Kanagawa Tetsuya
Published: November 2019

Oscillation of microbubbles in bubbly liquids induces a dispersion effect of waves into weakly nonlinear pressure waves, and its propagation process is described by a KdV-Burgers (KdVB) equation for a long wave case. We numerically predict an evolution of waveform by solving the KdVB equation derived by Kanagawa et al. (2010, 2011) via a finite difference method. As a result, (i) an initial Gaussian waveform is distorted due to a nonlinear effect, and a steepening of waveform is observed on about 20 000 period; (ii) the dispersion effect is observed at a steep part of waveform, and its part becomes sharp as the initial void fraction increases; (iii) the initial waveform change into an attenuated soliton on about 100 000 period due to a dissipation effect, and the attenuation of soliton is noteworthy as the initial void fraction decreases; (iv) balance of the nonlinear, dispersion, and dissipation effects thereby forms an attenuated soliton, and its amplitude strongly depends on the value of the initial void fraction. Furthermore, the period of soliton formation depends on the type of initial waveform. Although the nonlinear, dissipation, and dispersion effects were qualitatively balanced in the KdVB equation, we conclude that these effects independently appear in the sound field.
Weakly nonlinear propagation of pressure waves in liquids containing translational bubbles acting a drag force
Authors: Yatabe Takahiro , Ayukai Takahiro , Kanagawa Tetsuya
Published: November 2019

Weakly nonlinear (i.e., finite but small amplitude) propagation of plane pressure waves in liquids uniformly containing many spherical microbubbles is theoretically investigated. Although the effects of a translation of bubbles and a drag force acting on bubbles are incorporated, the creation, extinction, coalescence, break up, and polydispersity of bubbles are not considered. From the second order of approximation based on the method of multiple scales, the KdV–Burgers equation for a low frequency long wave is derived from the basic equations for bubbly flows composed of the conservation equations in a two-fluid model installing a virtual mass force and the bubble-dynamics equation for spherical symmetric oscillating translational bubbles. As a result, the translation of bubbles increased an effect of wave nonlinearity in a far field.
Design simulations for a combined shaker-acoustic vibration test technique
Authors: Schultz Ryan
Published: November 2019

A novel approach of combining multiple shaker and acoustic inputs can achieve a high-fidelity ground vibration test. Additionally, supplementing acoustic inputs with shakers enables higher response levels which is possible with shakers alone. As this is a new testing concept, exploring test design effects using simulations is useful. Here, models and simulation are utilized to explore how combining shaker and acoustic inputs can improve response levels and reduce input requirements while maintaining test accuracy. The derivation of acoustic and shaker inputs is explored using different control or input estimation techniques. In particular, the correlation requirements between shaker and acoustic inputs is examined using a Kronecker product formulation of the control problem, which enables specific inputs to be uncorrelated. This simulation-based test design approach provides useful guidance in the design of combined shaker-acoustic vibration tests. [Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under Contract No. DE-NA0003525.]
The post-PAM interaction of RNA-guided spCas9 with DNA dictates its target binding and dissociation
Authors: Zhang Qian , Wen Fengcai , Zhang Siqi , Jin Jiachuan , Bi Lulu , Lu Ying , Li Ming , Xi Xu-Guang , Huang Xingxu , Shen Bin , Sun Bo
Published: November 2019

This work determines the interactions between spCas9/sgRNA and DNA that dictate spCas9 binding and dissociation.
Fibrinogen-like protein 2 controls sepsis catabasis by interacting with resolvin Dp5
Authors: Zhou Yu , Lei Juan , Xie Qichao , Wu Lei , Jin Shengwei , Guo Bo , Wang Xiang , Yan Guifang , Zhang Qi , Zhao Huakan , Zhang Jiangang , Zhang Xiao , Wang Jingchun , Gu Jiaqi , Liu Xiaoli , Ye Duyun , Miao Hongming , Serhan Charles N. , Li Yongsheng
Published: November 2019

The dynamic expression of Fgl2 and RvDp5 synergistically programs inflammation resolution to restore homeostasis.
Evolutionarily conserved regulation of sleep by epidermal growth factor receptor signaling
Authors: Lee Daniel A. , Liu Justin , Hong Young , Lane Jacqueline M. , Hill Andrew J. , Hou Sarah L. , Wang Heming , Oikonomou Grigorios , Pham Uyen , Engle Jae , Saxena Richa , Prober David A.
Published: November 2019

Epidermal growth factor receptor signaling regulates sleep homeostasis in zebrafish and is implicated in regulating human sleep.
Role of climate in the rise and fall of the Neo-Assyrian Empire
Authors: Sinha Ashish , Kathayat Gayatri , Weiss Harvey , Li Hanying , Cheng Hai , Reuter Justin , Schneider Adam W. , Berkelhammer Max , Adalı Selim F. , Stott Lowell D. , Edwards R. Lawrence
Published: November 2019

Climate change played an important causal role in the expansion and collapse of the Neo-Assyrian Empire.
In vivo changes of nanoapatite crystals during bone reconstruction and the differences with native bone apatite
Authors: Li Xiyu , Zou Qin , Chen Haifeng , Li Wei
Published: November 2019

Notable differences exist between synthetic and native apatite in their crystal size and state of existence in bone tissue.
Neurogenesis and prolongevity signaling in young germ-free mice transplanted with the gut microbiota of old mice
Authors: Kundu Parag , Lee Hae Ung , Garcia-Perez Isabel , Tay Emmy Xue Yun , Kim Hyejin , Faylon Llanto Elma , Martin Katherine A. , Purbojati Rikky , Drautz-Moses Daniela I. , Ghosh Sujoy , Nicholson Jeremy K. , Schuster Stephan , Holmes Elaine , Pettersson Sven
Published: November 2019

Transplantation of the gut microbiota of old donor mice into young germ-free mice promotes neurogenesis and prolongevity gene expression signatures.
Relationship between popularity and the likely efficacy: an observational study based on a random selection on top-ranked physical activity apps
Authors: Bondaronek Paulina , Slee April , Hamilton Fiona L , Murray Elizabeth
Published: November 2019

Objectives

To explore the relationship between popularity of mobile application (apps) for physical activity (PA) and their likely efficacy. The primary objective was to assess the association between app popularity (indicated by user ratings) and likely efficacy (indicated by the number of Behaviour Change Techniques (BCT) present). The secondary objective was to assess the relationship between user ratings and those BCTs that have been shown to be effective in increasing PA.

Design

Observational study.

Methods

400 top-ranked free and paid apps from iTunes and Google Play stores were screened, and were included if the primary behaviour targeted was PA and they had stand-alone functionality. The outcome variable of user rating was dichotomised into high (4, 5 stars) or low (1, 2, 3 stars) rating.

Setting

iTunes and Google Play app stores.

Participants

No individual participants but the study used user-led rating system in the app store.

Primary and secondary outcome measures

BCTs and user rating.

Results

Of 400 apps, 156 were eligible and 65 were randomly selected, downloaded and assessed by two reviewers. There was no relationship overall between star ratings and the number of BCTs present, nor between star ratings and the presence of BCTs known to be effective in increasing PA. App store was strongly associated with star ratings, with lower likelihood of finding 4 or 5 stars in iTunes compared with Google Play (OR 0.74, 95% CI 0.73 to 0.76, p<0.001).

Conclusions

The findings of this study suggest that popularity does not necessarily imply the likelihood of effectiveness. Hence, public health impact is unlikely to be achieved by allowing market forces to ‘prescribe’ what is used by the public.
Neighbourhood socioeconomic status and overweight/obesity: a systematic review and meta-analysis of epidemiological studies
Authors: Mohammed Shimels Hussien , Habtewold Tesfa Dejenie , Birhanu Mulugeta Molla , Sissay Tesfamichael Awoke , Tegegne Balewgizie Sileshi , Abuzerr Samer , Esmaillzadeh Ahmad
Published: November 2019

Objective

Low neighbourhood socioeconomic status (NSES) has been linked to a higher risk of overweight/obesity, irrespective of the individual’s own socioeconomic status. No meta-analysis study has been done on the association. Thus, this study was done to synthesise the existing evidence on the association of NSES with overweight, obesity and body mass index (BMI).

Design

Systematic review and meta-analysis.

Data sources

PubMed, Embase, Scopus, Cochrane Library, Web of Sciences and Google Scholar databases were searched for articles published until 25 September 2019.

Eligibility criteria

Epidemiological studies, both longitudinal and cross-sectional ones, which examined the link of NSES to overweight, obesity or BMI, were included.

Data extraction and synthesis

Data extraction was done by two reviewers, working independently. The methodological quality of included studies was assessed using the Newcastle-Ottawa Scale for the observational studies. The summary estimates of the relationships of NSES with overweight, obesity and BMI statuses were calculated with random-effects meta-analysis models. Heterogeneity was assessed by Cochran’s Q and I2statistics. Subgroup analyses were done by age categories, continents, study designs and NSES measures. Publication bias was assessed by visual inspection of funnel plots and Egger’s regression test.

Result

A total of 21 observational studies, covering 1 244 438 individuals, were included in this meta-analysis. Low NSES, compared with high NSES, was found to be associated with a 31% higher odds of overweight (pooled OR 1.31, 95% CI 1.16 to 1.47, p<0.001), a 45% higher odds of obesity (pooled OR 1.45, 95% CI 1.21 to 1.74, p<0.001) and a 1.09 kg/m2increase in mean BMI (pooled beta=1.09, 95% CI 0.67 to 1.50, p<0.001).

Conclusion

NSES disparity might be contributing to the burden of overweight/obesity. Further studies are warranted, including whether addressing NSES disparity could reduce the risk of overweight/obesity.

PROSPERO registration number

CRD42017063889
Rehabilitation during intensive treatment of acute leukaemia including allogenic stem cell transplantation: a qualitative study of patient experiences
Authors: Jepsen Lene Østergaard , Friis Lone Smidstrup , Hoybye Mette Terp , Marcher Claus Werenberg , Hansen Dorte Gilså
Published: November 2019

Objectives

The diagnosis and treatment of acute leukaemia (AL) affect physical, psychosocial and existential functioning. Long-lasting treatment periods with impaired immune system, hygienic and social restrictions challenge patient well-being and rehabilitation as compared with other individuals with cancer. This study elucidates how AL patients, treated with curative intent in an outpatient setting, assess their physical, psychosocial and existential capability during and following treatment, and furthermore reports on the health initiatives offered to support their rehabilitation.

Design, setting, participants and interventions

We conducted qualitative, semi-structured individual interviews with 16 AL patients, 6 months after end of treatment in the patients’ homes. This was the final interview, in a line of three, carried out as part of a larger qualitative study.

Results

The data were analysed thematically through an inductive ongoing process consisting of four steps. The final step, selective coding, resulted in the three categories: physical activity, mental well-being and social activity. None of the patients were satisfied with their physical capability at the time of interview and experienced substantial impairment of functional capabilities. All patients struggled with anxiety and expressed a need for continuous progress in treatment and well-being to feel safe. It took an unexpected large effort to regain a meaningful social life, and patients still had to prioritise activities.

Conclusions

AL patients suffered physically, psychologically and existentially throughout their illness trajectory. Rehabilitation initiatives deriving from the healthcare system and municipalities held room for improvement. Future programmes should pay attention to the contextual changes of treatment of this patient group and individuals’ changing needs and motivation of physical exercise.
Migration status and healthcare seeking behaviours among the Chinese labor-force: a nationally representative study
Authors: Peng Boli , Zhang Hui , Shi Lishuo , Ling Li
Published: November 2019

Objectives

We aimed to analyse the healthcare seeking behaviours (HSB) of populations with different migration status and examine the relationship between migration status and HSB.

Design

A secondary analysis of cross-sectional data of China Labor-force Dynamics Survey wave 2016, which was conducted by the Sun Yat-sen University every 2 years since 2010.

Setting

29 provinces/cities/autonomous regions in mainland China, excluding Tibet and Hainan province.

Participants

3522 respondents in a condition in the previous 2 weeks or during the last 12 months were analysed.

Main outcome measures

The migration status included internal migrants (IMs), returned population, rural residents and urban residents. The HSB including health services utilisation and choice of health facilities for their health services. Multivariable logistic regressions were used to examine the association between migration status and HSB.

Results

2193 and 1898 of 3522 respondents were in need of outpatient services (having a condition in the previous 2 weeks) or inpatient services (being asked to use the inpatient services during the last 12 months). Compared with urban residents, the returned population (OR=0.66, 95% CIs 0.49 to 0.89) and rural residents (OR=0.65, 95% CIs 0.51 to 0.82) were less likely to have an unmet need for outpatient services. The latter tended to choose lower-level hospitals, while the IMs preferred the lowest-level healthcare facilities for health services. After controlling for confounding factors, the results above did not reach any statistical significance.

Conclusion

Association between migration status and HSB might be through enabling resource and needs. Returned population, IMs and rural residents tended to choose low-level hospitals for their health service needs, but this association was mainly associated with their poorer social and economic resources. Improving their social and economic resources would be helpful for reducing the barriers of HSB.