bluuebunny/crossref_metadata_2025 huggingface dataset:
Biologically Inspired Design and Development of a Variable Stiffness Powered Ankle-Foot Prosthesis
Authors: Agboola-Dobson Alexander , Wei Guowu , Ren Lei
Published: April 2019

Recent advancements in powered lower limb prostheses have appeased several difficulties faced by lower limb amputees by using a series-elastic actuator (SEA) to provide powered sagittal plane flexion. Unfortunately, these devices are currently unable to provide both powered sagittal plane flexion and two degrees of freedom (2-DOF) at the ankle, removing the ankle’s capacity to invert/evert, thus severely limiting terrain adaption capabilities and user comfort. The developed 2-DOF ankle system in this paper allows both powered flexion in the sagittal plane and passive rotation in the frontal plane; an SEA emulates the biomechanics of the gastrocnemius and Achilles tendon for flexion while a novel universal-joint system provides the 2-DOF. Several studies were undertaken to thoroughly characterize the capabilities of the device. Under both level- and sloped-ground conditions, ankle torque and kinematic data were obtained by using force-plates and a motion capture system. The device was found to be fully capable of providing powered sagittal plane motion and torque very close to that of a biological ankle while simultaneously being able to adapt to sloped terrain by undergoing frontal plane motion, thus providing 2-DOF at the ankle. These findings demonstrate that the device presented in this paper poses radical improvements to powered prosthetic ankle-foot device (PAFD) design.
Frequency Response-Based Uncertainty Analysis of Vibration System Utilizing Multiple Response Gaussian Process
Authors: Pan Wangbai , Tang Guoan , Tang Jiong
Published: April 2019

This research concerns the uncertainty analysis and quantification of the vibration system utilizing the frequency response function (FRF) representation with statistical metamodeling. Different from previous statistical metamodels that are built for individual frequency points, in this research we take advantage of the inherent correlation of FRF values at different frequency points and resort to the multiple response Gaussian process (MRGP) approach. To enable the analysis, vector fitting method is adopted to represent an FRF using a reduced set of parameters with high accuracy. Owing to the efficiency and accuracy of the statistical metamodel with a small set of parameters, Bayesian inference can then be incorporated to realize model updating and uncertainty identification as new measurement/evidence is acquired. The MRGP metamodel developed under this new framework can be used effectively for two-way uncertainty propagation analysis, i.e., FRF prediction and uncertainty identification. Case studies are conducted for illustration and verification.
Western North Atlantic humpback whale fall and spring acoustic repertoire: Insight into onset and cessation of singing behavior
Authors: Kowarski Katie , Moors-Murphy Hilary , Maxner Emily , Cerchio Salvatore
Published: April 2019

Humpback whale songs have been described worldwide and studies exploring non-song vocal behavior continue to expand; however, studies on the transition periods when whales shift to and from the seasonal behavioral state of singing are lacking and may be potentially informative regarding the proximal factors controlling the onset and offset of humpback whale male singing. Acoustic recorders collected data off eastern Canada continuously from the Bay of Fundy in the fall of 2015 and near-continuously off northeast Nova Scotia in the spring of 2016. Humpback whale acoustic occurrence and behavior were identified by systematically reviewing a subset of acoustic recordings for presence before analyzing the highest quality recordings for behavior. The onset of singing in the fall was gradual over a period of about three weeks with an intermediate form, termed “song fragment,” occurring prior to full songs. In comparison, singing in the spring seemed to end abruptly with few song fragments. Song fragments could be produced by juveniles learning to sing for the first time or mature males preparing for breeding activities prior to migrating to southern breeding grounds. The authors propose an alternative hypothesis that the timing and manner of transitions could be driven by physiological processes similar to those documented in songbirds.
Neural correlates of auditory enhancement
Authors: Mehta Anahita H. , Oxenham Andrew J.
Published: April 2019

Auditory enhancement is the increase in salience of a target embedded in a simultaneous masker that occurs when a copy of the masker, termed the precursor, is presented first. The effect reflects the general principle of contrast enhancement and may help in the perceptual constancy of speech under varying acoustic conditions. The physiological mechanisms underlying auditory enhancement remain unknown. This study investigated EEG responses under conditions that elicited perceptual enhancement. The target tone was amplitude-modulated at two modulation frequencies to target cortical (~40 Hz) and subcortical (100–200 Hz) responses. Measurements were made in either passive conditions or under active tasks to examine the potential effects of attention on the neural correlates of enhancement. Robust effects of enhancement were observed at the cortical level, replicating our earlier findings. Preliminary data under passive conditions also suggest a trend towards increased neural response to the enhanced target tone at frequencies exceeding 200 Hz, suggesting a subcortical contribution. The results suggest that this paradigm can be used to tap into the neural correlates of auditory enhancement at both cortical and subcortical levels simultaneously and show the potential for tapping into attentional modulation of auditory enhancement. [Work supported by NIH grant R01DC012262.]
An overview of isolation controls at LIGO
Authors: Pele Arnaud
Published: April 2019

The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment that aims at measuring gravitational waves emitted by astrophysical sources. The detection of black hole mergers and neutron star collision was made possible by the extreme level of isolation required to hold the optics still from external ground disturbances in a large band of the spectrum. From the low-frequencies (earthquakes, wind, microseism, below 1 Hz) to the higher frequencies (anthropogenic noise, above 1 Hz), the controls system must be tuned to meet the requirements for lock acquisition, lock stability, and sensitivity of the instrument. In this talk, I will describe the overall control scheme of the LIGO isolation platforms and mirror suspensions, and the challenges met to design the many feedback and feedforward control loops.
Mechanics and dynamics of reconfigurable curved creased origami arrays
Authors: Filipov Evgueni T. , Woodruff Steven R.
Published: April 2019

The principles of origami have allowed for novel deployable and reconfigurable structures with applications from micro-robotics to adaptable architecture. Most origami patterns use rigorous mathematical definitions to achieve their desired folding kinematics; however, these geometries result in discrete and segmented structures that have sharp edges. In contrast, curved creased origami uses a more arbitrary placement of folds and can thus achieve smooth surfaces. These smooth surfaces can be useful for problems in acoustics, fluid flow, electromagnetics, wave-propagation, and more. In this talk, we first explore the geometry of the curved crease origami, where continuous curvatures and elastic bending occur over the entire surface of the thin sheet. We use a simplified bar and hinge model to approximate the folding sequence and model the behaviors of the curved crease origami. The model captures stretching and shearing of the origami, bending along principle curvature directions, and bending at the prescribed curved creases. We explore the stiffness, large deformation mechanics, buckling, and dynamic behaviors of the curved crease origami. Our results show that the curved folding can enable highly tuneable properties for these novel thin-sheet arrays.
Improving speech intelligibility performance for aircraft maintainers by selecting an appropriate combination of hearing protection devices
Authors: Gallagher Hilary , Swayne Billy
Published: April 2019

Aircraft maintainers work in hazardous noise environments throughout their career. Hazardous noise levels on the flight line vary, affecting the level of hearing protection required to reduce their risk of hearing loss and other hearing related disabilities. Current practice is to provide double hearing protection: a circumaural headset/earmuff with foam earplugs. This combination may provide an adequate amount of protection from aircraft noise, but the proper use of foam earplugs may degrade speech intelligibility (SI) performance. Due to this degradation, many maintainers fit the foam earplugs incorrectly in order to improve SI performance, therefore lowering the amount of protection provided. The objective of this study was to assess the noise attenuation and SI performance of a headset and filtered earplugs worn alone and in combination to provide a more appropriate recommendation of hearing protection devices. The filtered earplug can provide suitable levels of protection when worn alone or in combination with a headset (depending on the noise environment) and can provide adequate “hear through” capability for acceptable SI performance when communicating face-to-face (single hearing protection) or through the aircraft communication system (double hearing protection).
Acoustic validation of military aircraft noise models
Authors: Wall Alan T. , Mobley Frank S.
Published: April 2019

The National Environmental Policy Act (NEPA) of 1970 established the requirement to assess noise impacts from aircraft operations on the community surrounding military bases. A process for measuring and modeling aircraft noise sources and their propagation to ground locations was developed in response. The NOISEMAP suite of software programs produces noise footprints of yearly average impacts due to all flights that occur to and from an airbase. Through NOISEMAP’s decades of evolution, it retains the same fundamental measurement/modeling architecture and remains the approved model for environmental impact studies for aircraft within the U.S. Department of Defense (DoD). However, new advanced source and propagation models exist, which result in lower uncertainties and the calculation of additional useful noise impact metrics. No clear path exists to allow the use of these models for DoD environmental impact studies. This work presents a scientific validation experiment for aircraft overflight source/propagation models, focusing on suitability for use in a NEPA environmental impact study. The experiment relies on high-fidelity data collected during controlled overflight acoustic measurements of real aircraft and provides a quantitative benchmark for the evaluation of future models.
Acoustical modeling considerations in noise assessment of live fire training ranges
Authors: White Michael J. , Swearingen Michelle E.
Published: April 2019

In the US, long-term noise assessments near military firing ranges are required to estimate the weighted average of simulated sounds from thousands of noise-producing activities. Each of these activities are modeled with a set of parameters and heuristics. Parameters include source type, including quantification of firing and munition explosive charges; location information; high or low angle of fire designation; and basic environmental conditions including time of day, time of year, generalized surface type, and some meteorological information. Heuristics model the source strength and directivity, divergence of waves, ground reflection, atmospheric refraction, absorption of sound, and shielding by noise barriers and terrain. The heuristics represent limitations to the fidelity of the modeling result, and they produce estimates with significant uncertainties. In view of the uncertainties, validation of results is particularly difficult and must be performed on single activity calculations rather than long-term averages. To evaluate the uncertainty, we compare single event calculations to controlled measurements, thereby minimizing the parameter uncertainty. These ideas are discussed, and an assessment of the model uncertainty is presented.
The unusual properties of liquid helium
Authors: Garrett Steven L.
Published: April 2019

Each year since 1925, one UCLA faculty member has been selected to present the Faculty Research Lecture. In 1976, Isadore Rudnick was so honored. As an experimentalist, Izzy chose to make his presentation a lecture demonstration, like those of Michael Faraday’s famous Christmas presentations at the Royal Society in London. This required that an entire low-temperature laboratory be recreated on the stage of Schoenberg Hall, including a transparent Dewar vessel. The success of those live demonstrations, and the fact that two of Izzy’s sons were film makers, prompted him to make a 17-min film version of those demonstrations. That film won the award for best Technical and Scientific Film at the 21st Annual San Francisco International Film Festival, in 1977. Also, at this same time, the Cultural Revolution in China had ended, and Izzy was one of the first U.S. physicists invited to lecture there. As a gift to his Chinese hosts, he had this film translated into Mandarin. Due to the scarcity of the material available for those early Chinese television broadcasts, the film was played frequently, and Izzy became a TV celebrity throughout China. The film, shown in this talk, is included in ASA’s Collected Works of Isadore Rudnick.
Design and experimental validation on acoustic valley Hall edge states in reconfigurable phononic elastic waveguides
Authors: Liu Ting-Wei , Semperlotti Fabio
Published: April 2019

We report on the design and experimental validation of a tunable topological elastic lattice capable of supporting guided waves that are robust against back-scattering from disorder and defects. The topological lattice consists in a patterned aluminum thin plate having through-holes arranged in a hexagonal periodic configuration. The occurrence of the topological edge state is attributed to the acoustic analogue of the electron quantum valley Hall effect. By connecting two lattices having broken space inversion symmetry due to the application of opposite tunable strain fields, a topological transition emerges at the domain wall (i.e., the interface between them). Such a domain wall supports the formation and propagation of quasi-unidirectional edge states. The experimental validation of the topological waveguide is conducted on an aluminum plate that is already fabricated in a deformed (i.e., broken symmetry) configuration. The results confirm the existence of quasi-unidirectional edge states traveling along the domain wall and robust against sharp corners back-scattering. The experimental results also confirm the presence of mechanical energy flux vortices within the unit cell that are used to investigate the origin of the edge states robustness against disorder.
Application of adaptive line spectrum enhancer in adaptive matched filter
Authors: Zhang Xiaoliang , Hui Juan , Li JiangQiao , Li Huangpu , Bu Xianzhong
Published: April 2019

The most classical detector of active sonar and radar is the matched filter (MF), which is the optimal processor under ideal conditions. Aiming at the problem of active sonar detection, we propose a frequency-domain adaptive matched filter (FDAMF) with the use of a frequency-domain adaptive line enhancer (ALE). The FDAMF is an improved MF. In the simulations in this paper, the signal to noise ratio (SNR) gain of the FDAMF is about 18.6 dB higher than that of the classical MF when the input SNR is -10 dB. In order to improve the performance of the FDAMF with a low input SNR, we propose a pre-processing method, which is called frequency-domain time reversal convolution and interference suppression (TRC-IS). Compared with the classical MF, the FDAMF combined with the TRC-IS method obtains higher SNR gain, a lower detection threshold, and a better receiver operating characteristic (ROC) in the simulations in this paper. The simulation results show that the FDAMF has higher processing gain and better detection performance than the classical MF under ideal conditions. The experimental results indicate that the FDAMF does improve the performance of the MF, and can adapt to actual interference in a way. In addition, the TRC-IS preprocessing method works well in an actual noisy ocean environment.
The soundscape standard—Its development and challenges
Authors: Schulte-Fortkamp Brigitte
Published: April 2019

Soundscape entered the debate of noise annoyance issues in the nineties, most likely at the same time as when the EU Directive 2002/49/EC [PJ1] on Noise was under development. In 2014, the ISO standard ISO 12913-1: “Acoustics-Soundscape-Part 1: Definition and conceptual framework” was published, delivering the first framework for soundscape. This was followed in 2018 by “ISO/TS 12913-2 Acoustics—Soundscape—Part 2: Data collection and reporting requirements”, which provided evaluation processes and information for integrating stakeholder participation. The third part of the standard is now underway: ISO/ TS 12913-3 “Acoustics- Soundscape—Part 3: Data analysis.” Together, the international standard ISO 12913 provides guidance for accessing the key components in soundscape: people, acoustic environment, and context. The available standards in soundscape, psychoacoustics and noise management have provided a large step towards enhancing the quality of life for people. the urgent need for recognition but also for application with regard to new understandings of urbanism will be discussed.
Flaws in the use of spectral ripples in cochlear implants
Authors: Winn Matthew , O'Brien Gabrielle
Published: April 2019

Spectral ripple discrimination is a popular measure of spectral resolution that has been shown to correlate with speech recognition scores in cochlear implant (CI) listeners. In the test, listeners distinguish sounds with varying density of spectral peaks, with some spectral modulation depth. We argue that there are numerous significant flaws with the application of the test specifically in CI listeners. To start, the spectrum is aliased by the CI processor in a way that is similar to frequency aliasing for under-sampled time series. Beyond a critical spectral density, the spectral envelope changes in a chaotic fashion and is no longer under experimenter control. This critical density is exceeded in numerous published studies. Furthermore, the densities linked with “good” performance are not only outliers, but are entirely unrelated to the spectral densities of real speech sounds, and likely exhibit undue leverage over correlation values. Additionally, there are reports of experience and learning effects, inconsistent with the often-stated goals of the test to avoid such factors. We show how artefactual nonlinearities at high spectral densities may unintentionally match the spectral envelope characteristics of speech sounds—an unfortunate result that likely has given spurious results that sustain the use of this test.
Using acoustic features of mothers’ infant-directed speech to predict changes in infant biobehavioral state
Authors: Kolacz Jacek , daSilva Elizabeth B. , Lewis Gregory F. , Bertenthal Bennett I. , Porges Stephen W.
Published: April 2019

Infant directed speech is marked by exaggerated frequency modulation and strong high frequency power, features that may provide physiological cues for mobilization or calming (Porges and Lewis, 2010; Kolacz et al., 2018). We examined whether these features predicted changes in infant biobehavioral state during the Still Face Paradigm, a stressor in which the mother withdraws and reinstates social cues. 98 mother-infant dyads participated when infants were 4-8 months old. Infant heart rate and respiratory sinus arrhythmia (a measure of cardiac parasympathetic control) were derived from an electrocardiogram (ECG). Infant behavioral distress was measured by vocal, facial, and body movement distress. Mothers’ vocalizations were measured using spectral analysis within designated frequency bands and modulation using a 2-dimensional fast Fourier transform of the audio spectrogram. Maternal frequency modulation predicted decreases in infant heart rate (p = .030), mid-frequency acoustic power (500–5000 Hz) predicted increases in cardiac parasympathetic regulation in infants with low parasympathetic tone (p = .024), and high frequency power predicted increases in infant behavioral distress in infants who were not initially distressed (p = .011). These results suggest that mothers’ vocal frequency band power and modulation may be aspects of infant-directed speech that are relevant for regulating infant biobehavioral state.
Acoustic reflectivity of a harbor porpoise Phocoena phocoena
Authors: Au Whitlow , Kastelein Ronald , Helder-Hoek Lean
Published: April 2019

Acoustic backscatter measurements were conducted on a stationary harbor porpoise (Phocoena phocoena) under controlled conditions. The measurements were made with the porpoise in the broadside aspect using three different types of signals as follows: (1) a 475-ms linear frequency-modulated (FM) pulse with a frequency range from 23 to 160 kHz; (2) a simulated bottlenose dolphin (Tursiops truncates) click with a peak frequency of 120 kHz; and (3) a simulated killer whale (Orcinus orca) click with a peak frequency of 60 kHz. The measurement with the FM pulse indicated that the mean target strength at the broadside aspect decreased from -26 dB to -50 dB as the frequency increased from 23 to 120 kHz in a nearly linear fashion (on a logarithm plot) and dropped rapidly by 27 dB to -77 dB at 150 kHz. Target strength variation with the frequency was similar to that in a previous backscatter measurement performed on a bottlenose dolphin over a similar frequency range (23–80 kHz). The target strength of the smaller harbor porpoise was about 15–16 dB lower than that of the bottlenose dolphin. The difference in the lung volume of the two species when expressed in dB was also approximately 15 dB. The results suggest that the dolphin bubbrt had broadband anechoic properties.
Developing a biomimetic acoustic deterrent to reduce bat mortalities at wind turbines
Authors: Smotherman Michael , Sievert Paul , Dowling Zara , Carlson Dan , Modarres-Sadeghi Yahya
Published: April 2019

High bat mortalities at wind turbines have emerged as an unexpectedly severe environmental impact of developing wind farms all over the world, motivating an urgent need to develop effect deterrent strategies that can be implemented efficiently on a large scale. Echolocating bats use ultrasonic sonar to navigate, and some studies have shown that broadband ultrasonic noise can have a deterrent effect under certain conditions. Thus, ultrasonic noise may be an attractive approach, but attempts to incorporate electronic sound generating solutions have generally failed because of insufficient bandwidth and intensity as well as their sensitivity to the harsh environmental conditions. To get around these constraints, we designed a biomimetic whistle loosely modeled after the bat larynx that could be mounted on the moving turbine blades to passively generate ultrasonic sounds tuned to the acoustic parameters of bat’s auditory system. The whistle produces multi-harmonic tones detectable by the most impacted bat species from distances approaching 100 me away. To test whether the whistle actually deters bats or alters their flight paths, we conducted a series of playback studies in the lab and field using microphone arrays and videography. This presentation will focus on the results of these behavioral studies assessing whether or not bats change their flight trajectories in response to hearing the acoustic stimulus produced by the whistle.
Super-resolution approaches in photoacoustic imaging
Authors: Arnal Bastien , Vilov Sergey , Godefroy Guillaume , Bossy Emmanuel
Published: April 2019

The resolution of photoacoustic imaging (PAI) is limited at depths by the diffraction limit. Several ways have been introduced to achieve super-resolution. In the context of imaging the vasculature, the presence of flow can be exploited in two regimes, distinct by the concentration of flowing absorbing particles. In the high concentration regime, we proposed to exploit the absorption fluctuation caused by flowing absorbers by analyzing nth-order statistics of temporal signal fluctuations. In the low concentration regime, when absorbers appear one-by-one in each acoustic resolution spots, the localization microscopy technique can be adapted to our problem. While these two methods improve the resolution greatly, their cost is to reduce temporal resolution, because of the need to record thousands of images. Supposing the knowledge of the PSF (point spread function) of the imaging system, it is possible to the regain temporal resolution. After the simulation of the forward model, the imaged object can be recovered by solving a minimization problem. We will show that adding a sparsity constraint to this problem can enhance the resolution. These techniques have been investigated in both simulations and experiments in microfluidic channels. Such super-resolution approaches bring the optical contrast at depth closer to the cellular level.
Polyphonic pitch perception in rooms using deep learning networks with data rendered in auditory virtual environments
Authors: Keil Nathan , Dahlbom David A. , Stewart Jeremy , Goodheart Matthew , Bahn Curtis , Simoni Mary , Perrone Michael , Braasch Jonas
Published: April 2019

This paper proposes methods for generation and implementation of uniform, large-scale data from auralized MIDI music files for use with deep learning networks for polyphonic pitch perception and impulse response recognition. This includes synthesis and sound source separation of large batches of multitrack MIDI files in non-real time, convolution with artificial binaural room impulse responses, and techniques for neural network training. Using ChucK, individual tracks for each MIDI file, containing the ground truth for pitch and other parameters, are processed concurrently with variable Synthesis ToolKit (STK) instruments, and the audio output is written to separate wave files in order to create multiple incoherent sound sources. Then, each track is convolved with a measured or synthetic impulse response that corresponds to the virtual position of the instrument in the room before all tracks are digitally summed. The database now contains the symbolic description in the form of MIDI commands and the auralized music performances. A polyphonic pitch model based on an array of autocorrelation functions for individual frequency bands is used to train a neural network and analyze the data [Work supported by IBM AIRC grant and NSF BCS-1539276.]
A real-time, automated tongue tracking method for ultrasound biofeedback in speech therapy
Authors: Masterson Jack A. , Li Sarah R. , Woeste Hannah M. , Dugan Sarah , Mahalingam Neeraja , Boyce Suzanne E. , Riley Michael A. , Mast T. Douglas
Published: April 2019

Midsagittal ultrasound images of the tongue surface are currently used as feedback on tongue motion for speech therapy, but can be difficult to interpret. Ultrasound biofeedback would benefit from a simplified, immediate representation of tongue motion. Tongue tracking in ultrasound is complicated by reflections from structures near the tongue surface, complex tongue shapes, and rapid, extreme tongue movements. Available programs that trace contours of the tongue surface have not been implemented in real time and can require extensive user input. We offer a tongue tracking method that can operate in real time and requires minimal user input. This method applies a low-pass filter to the B-mode image and then maps the tongue surface based on local brightness maxima within search regions estimated by 2nd-order Taylor series expansions in space and time. Required user input includes a graphically selected calibration point near the tongue surface and relative brightness thresholds for anterior and posterior ends of the tracked surface. Preliminary results show that this method can capture complex, rapid movements of tongue parts during production of American English /r/. Efficient tongue tracking enables real-time analysis of tongue dynamics, offering a valuable tool for speech therapy.
Adaptive reuse of unconventional spaces for performance: Music in a museum and opera in a warehouse
Authors: Underwood Samuel H. , Smith Kieren H. , Wang Lily M.
Published: April 2019

Taking a space designed for one purpose and creating an acoustically sound space for musical performance presents unique challenges. A local opera company has undertaken two projects that involve such modifications for this performance season and have sought guidance on the unique acoustic complications involved. The first project was a percussive musical playground in a large art museum, adjacent to sound-sensitive exhibits. The second involved the adaptation of an existing warehouse into a space suitable for the performance of a ballet-opera. Researchers worked with set designers early in the process and throughout set construction. In order to better understand the spaces, impulse responses were taken and analyzed. Impulse response measurement results, acoustic models with suggested modifications, and auralizations at key listening positions are presented to address unique challenges associated with these unconventional spaces. An emphasis has been placed on reaching target values for reverberation time within limited time and resource constraints. Additionally, sound isolation for the two spaces has been addressed with special regard to adjacencies and noises in industrial downtown locations.
HIFU tissue lesion quantification by optical coherence tomography
Authors: Raymond Jason L. , Everbach E. Carr , Roy Ronald , Marques Manuel , Hughes Michael , Podoleanu Adrian
Published: April 2019

Heating of tissue by high-intensity focused ultrasound (HIFU) can result in sufficient temperature elevation to cause irreversible changes in the tissue structure. The contiguous volume occupied by these changes, a lesion, and the extent of the tissue changes may be quantified histologically or estimated through techniques such as ultrasonic elastography. We have shown that changes in tissue optical scattering could be used as a proxy to improve sensing and imaging of HIFU lesion formation as an alternative to thermometry. Optical coherence tomography (OCT) is a light-based method appropriate for optically accessible tissues, which we have used to quantify lesion volume, shape, and quality based upon the irreversible changes in optical scattering that occurs with protein denaturation. We have adapted OCT to take into account changes in optical polarization of the tissue, providing sensitivity to changes in the collagen orientation of skin with heating. This technique has potential in detecting antecedents of skin burn during HIFU exposures, thereby increasing safety and reducing treatment times.
Analysis of increased damping in arrays of attached resonators
Authors: Sterling John A. , Vignola Joseph F. , Ryan Teresa J. , Paruchuri Sai T.
Published: April 2019

Research has shown that arrays of small dynamic attachments on a larger, primary structure can be tuned to significantly alter the time and frequency response of the system. Such attachments can be used to increase the apparent damping of a primary structure by transferring energy into the substructure and dissipating the energy there. By selecting the properties of the attachments to obtain specific distributions of element mass and mode frequency, the response of the primary structure can be altered to obtain specific spectral outcomes. Unfortunately, small errors in the distributions of mass and stiffness of the individual attachments have been shown to produce a significant degradation of intended performance. Until recently, metals were the practical option that was easily manufactured to the tolerances required. New three-dimensional-printing advancements have made plastics available with sufficient tolerances. A serendipitous discovery was that the increased damping shown in the plastics decreased the system’s sensitivity to error. Previous analysis assumed low damping in the attached resonators. This work will show analysis with moderate to high damping levels for the attachments. Here, we will show experimental results using different plastic materials with moderate dimensional error.
Second langauge production of French mid and high vowels: An articulatory perspective
Authors: Oakley Madeleine
Published: April 2019

This study uses Ultrasound Tongue Imaging and acoustic data to investigate the articulatory strategies used by L1 English L2 French learners to produce round vowels. It has been suggested that learners have more difficulty in producing L2 phones that are "similar" to L1 phones than L2 phones that are completely "new" because learners use L1 categories to produce L2 phones (Flege, 1982; Kamiyama and Vaissiere, 2009). However, this claim is based solely on acoustic data. To this end, the present study records learners' articulatory strategies using Ultrasound during production of French round vowels /y, u, ø, o/ compared to English /u, o/. 1 L1 French speaker and 6 L2 French learners were recorded producing wordlists in French and English, using ultrasound, video recordings of lip protrusion, and audio recordings. Results show that learners do not, in fact, use L1 articulatory strategies to produce L2 phones. Additionally, articulatory data show that learners still have difficulty producing target-like tongue positions for new phones, despite having target-like acoustic productions, which may suggest that non-native vowels have an acoustic rather than an articulatory target.
Effects of pitch contour and speaking rate on perception of foreign-accented speech
Authors: Davis Rebecca F. , Baese-Berk Melissa M. , Stilp Christian
Published: April 2019

Perception of foreign accent is typically studied using an accentedness rating task. For example, native English listeners rate the degree of accentedness in sentences produced by non-native English speakers. However, in the past studies, it has been unclear that on what criteria participants used to judge accentedness. Here, native English speakers rated the accentedness of Korean-accented English sentences on a scale from 1 (strong accent) to 9 (little to no accent). Participants rated sentences that were unmodified or had one acoustic property removed. In one block, pitch contours of sentences were flattened and set to their mean values. In another block, speaking rates were set to the grand mean of all speaking rates (3.8 syllables/second). This way, changes in accentedness ratings across unmodified and modified sentences were attributable to the acoustic property that was removed. Accentedness ratings were not systematically influenced by manipulations of pitch contours but were influenced by speaking rate manipulations. Increasing the speaking rate (to 3.8 syllables/second) made sentences sound less accented than their unmodified versions; decreasing the speaking rate made sentences sound more accented than their unmodified versions. Results suggest that the speaking rate directly contributes to ratings of foreign accentedness.
Echo-mode aberration tomography: Sound speed imaging with a single linear array
Authors: Podkowa Anthony , Oelze Michael
Published: April 2019

Tomographic sound speed imaging has previously demonstrated the capability of producing images of comparable quality to that of X-ray CT and MRI. Traditionally, such reconstructions have only been achievable in transmission mode, either using diametrically opposed linear arrays or ring arrays. This is due to the conventional wisdom that forward scatter data are necessary for reconstruction in the general case, and consequentially, such setups are typically limited to easily externalized, soft tissues such as the female breast and thus are impractical for clinical usage. Recently, it has been demonstrated that in the presence of diffuse scatterers (Jaeger, 2015), pulse-echo reconstructions of slowness (inverse sound speed, proportional to refractive index) is feasible with a conventional single conventional linear array. By correlating data acquired with steered plane wave transmissions, depth dependent maps of phase lags can be generated and subsequently used to solve a multilinear inverse problem. The resulting images allow for baseband, speckle-free characterization of the underlying medium, which is complementary to the data acquired in traditional B-mode ultrasound. In this presentation, the fundamentals of echo-mode aberration tomography will be reviewed, completely with algorithmic formulation, beamformation considerations, and current challenges in practical reconstruction.
Toroidal intra-operative high intensity focused ultrasound transducer for treating liver metastases under ultrasound imaging guidance: Clinical results of Phase II study
Authors: Melodelima David , Dupre Aurelien , Chen Yao , Perol David , Rivoire Michel
Published: April 2019

The aim of this study was to assess the feasibility, safety, and accuracy of HIFU ablation in patients with liver metastases in a prospective phase II trial. The transducer has a toroidal shape (diameter: 70 mm, radius of curvature: 70 mm) and was divided into 32 ring-shaped emitters operating at 2.5 MHz. Thirty-one patients were included. HIFU ablations were created to ablate metastases (up to 30 mm in diameter) with safety margins in all directions. The use of a toroidal transducer enables an ablation rate (10 cc min-1) significantly higher than spherical transducers. Therefore, using electronic focusing of the beam, it was possible to treat all metastases with safety margin without the need to displace the device between HIFU exposures. The exposure time varied from 40 s to 370 s according to the diameter of the metastases to be treated. The dimensions of these HIFU ablations were a diameter of 48 ± 4.9 mm and a long axis of 45 ± 3.4 mm. No damage occurred to neighboring tissues. This study is the first clinical use of intra-operative HIFU in patients with liver metastases.
Total hearing health: An approach for raising noise awareness in society
Authors: Themann Christa L.
Published: April 2019

Noise-induced hearing loss is one of the most common work-related illnesses in the United States, and an estimated 24% of hearing difficulty among the working population is attributable to workplace exposures. However, the harmful effects of noise are evident even among non-workers. Regardless of occupation, nearly everyone will encounter hazardous noise at some point during their lifetime. NIOSH promotes Total Hearing Health, which broadens the scope of hearing loss prevention interventions to encompass all risks to hearing, both at and away from work. This presentation will discuss tools for applying the Total Hearing Health approach to increasing noise awareness. These tools include (a) Apps and devices which measure noise exposure and provide information on hearing loss risk; (b) Promotional ideas to raise awareness of hearing health at worksites, classrooms, health fairs, sporting events, and other venues; and (c) Wikipedia, blogs, and social media tools for expanding the reach of hearing loss prevention messages. Increasing noise awareness requires engaging the public in an authentic and meaningful way. Examples of how NIOSH have implemented Total Hearing Health to accomplish this goal and recommendations for incorporating Total Hearing Health in your own work will be provided.
Context-dependent trading of binaural spatial cues in virtual reality
Authors: Moore Travis M. , Stecker G. Christopher
Published: April 2019

A classic paradigm used to quantify the perceptual weighting of binaural spatial cues requires a listener to adjust the value of one cue, while the complementary cue is held constant. Adjustments are made until the auditory percept appears centered in the head, and the values of both cues are recorded as a trading ratio, most commonly in µs ITD per dB ILD. Interestingly, the existing work has shown that TRs differ according to the cue being adjusted. The current study investigated whether cue-specific adaptation-which might arise due to the continuous, alternating presentation of signals during adjustment tasks-could account for this poorly understood phenomenon. Three experiments measured TRs via adjustment and via lateralization of single targets in virtual reality (VR). Targets were 500 Hz pure tones preceded by silence or by adapting trains that held one of the cues constant. VR removed visual anchors and provided an intuitive response technique during lateralization. The pattern of results suggests that adaptation can account for cue-dependent TRs. An adaptation-based theory states that the ITD contributes most to the TR during adjustment, and adjusting the ILD results in a TR reflects contributions from both the ITD and ILD. [Work supported by NIH R01 DC016643.]
Spatial release from masking and sound localization using real-time sensorineural hearing loss and cochlear implant simulation
Authors: Wright Hannah M. , Bulla Wesley , Tarr Eric W.
Published: April 2019

Simulations of sensorineural hearing loss (SNHL) and bilateral cochlear implantation (BCI) have been modeled successfully under static and non-real time conditions. This study performed two experiments testing the validity of a novel real-time SNHL/BCI simulation application for iOS using an in-ear binaural-recording headphone apparatus. The first experiment measured spatial release from masking (SRM) with normal hearing (NH), against headset apparatus simulations of NH, SNHL, and BCI using HINT sentences, speech shaped noise and forward masking. A one-sample t-test revealed significant differences between NH and simulated SNHL and BCI conditions showing reduced benefit from SRM. The second experiment employed noise bursts across nine frontal-plane loudspeakers and measured localization accuracy under NH and six frequency band BCI simulation conditions. Repeated measures two-way ANOVA and Cronbach’s Alpha suggested significantly reduced localization ability with BCI simulation. While further testing is needed, results here provide promising evidence that real-time binaural recording with low-latency processing and in-ear playback may be used to simulate SNHL and the BCI percept in NH listeners. The limitations and potential of this technology to expand the subject pool and expedite innovative testing are discussed.
Factors Leading to Discrepancies in Accumulated Physical Activity During School Hours in Elementary School Students
Authors: Galloway Riley , Booker Robert , Owens Scott
Published: April 2019

Purpose: Current in-school physical activity (PA) policies lack regulation, which testifies to the urgency of monitoring in-school moderate to vigorous PA (MVPA). This study quantifies the demographical differences of in-school PA among elementary students. Methods: Fourth-grade students wore accelerometers during school for 1 week. The teachers logged information for PA setting and duration of opportunity. Results: The accelerometry data (N = 148) showed alarming results in the lack of MVPA during in-school PA opportunity times. Significant sex differences showed boys to accumulate more minutes MVPA per day in recess than girls (7.62 ± 5.87 and 5.19 ± 3.03, respectively). Racial differences showed that non-White students accumulated significantly more minutes of MVPA per week during the school day than White students (30.82 ± 19.09 and 23.44 ± 18.41, respectively). Conclusions: The students fell short of the recommended 30 min of MVPA per day during school hours, as advised by a state mandate. Significant differences were seen in PA levels across sex and race, supporting the need for enhanced attention to influential factors on PA engagement.
Gender Differences in Sport Spectatorship and (Fe)male Adolescents’ Gender Identity, Experienced Pressure for Gender Conformity and Gender Role Attitudes
Authors: Lagaert Susan , Van Houtte Mieke , Roose Henk
Published: April 2019

We study (fe)male adolescents’ interest in watching sports as a spectator using logistic multilevel analyses based on a representative sample of 5837 Flemish (Belgian) pupils in the first year of secondary education. To uncover the mechanisms behind the ‘gendering’ of passive sports consumption, this study evaluates how the gender gap (characterized by higher male involvement) relates to the gender identity, experienced pressures for gender-conforming behavior and gender role attitudes of the students. Results indicate that the gender gap in interest is to a large extent related to the studied mechanisms. The findings have implications for research on the feminization of sports fandom and call for further analysis of the processes behind the gender gap in consumption of different sports with masculine or feminine connotations and of on-site and TV spectatorship.
Catalytic antimicrobial robots for biofilm eradication
Authors: Hwang Geelsu , Paula Amauri J. , Hunter Elizabeth E. , Liu Yuan , Babeer Alaa , Karabucak Bekir , Stebe Kathleen , Kumar Vijay , Steager Edward , Koo Hyun
Published: April 2019

Magnetically driven catalytic antimicrobial robots eliminate biofilms precisely via a synergistic “kill-degrade-remove” mechanism.
A BMP/activin A chimera is superior to native BMPs and induces bone repair in nonhuman primates when delivered in a composite matrix
Authors: Seeherman Howard J. , Berasi Stephen P. , Brown Christopher T. , Martinez Robert X. , Juo Z. Sean , Jelinsky Scott , Cain Michael J. , Grode Jaclyn , Tumelty Kathleen E. , Bohner Marc , Grinberg Orly , Orr Nadav , Shoseyov Oded , Eyckmans Jeroen , Chen Christopher , Morales Pablo R. , Wilson Christopher G. , Vanderploeg Eric J. , Wozney John M.
Published: April 2019

BV-265, a BMP-2/BMP-6/activin A chimera, delivered in a composite matrix generates bone repair in nonhuman primates at lower concentrations than BMP-2.
Diagnosis of genetic diseases in seriously ill children by rapid whole-genome sequencing and automated phenotyping and interpretation
Authors: Clark Michelle M. , Hildreth Amber , Batalov Sergey , Ding Yan , Chowdhury Shimul , Watkins Kelly , Ellsworth Katarzyna , Camp Brandon , Kint Cyrielle I. , Yacoubian Calum , Farnaes Lauge , Bainbridge Matthew N. , Beebe Curtis , Braun Joshua J. A. , Bray Margaret , Carroll Jeanne , Cakici Julie A. , Caylor Sara A. , Clarke Christina , Creed Mitchell P. , Friedman Jennifer , Frith Alison , Gain Richard , Gaughran Mary , George Shauna , Gilmer Sheldon , Gleeson Joseph , Gore Jeremy , Grunenwald Haiying , Hovey Raymond L. , Janes Marie L. , Lin Kejia , McDonagh Paul D. , McBride Kyle , Mulrooney Patrick , Nahas Shareef , Oh Daeheon , Oriol Albert , Puckett Laura , Rady Zia , Reese Martin G. , Ryu Julie , Salz Lisa , Sanford Erica , Stewart Lawrence , Sweeney Nathaly , Tokita Mari , Van Der Kraan Luca , White Sarah , Wigby Kristen , Williams Brett , Wong Terence , Wright Meredith S. , Yamada Catherine , Schols Peter , Reynders John , Hall Kevin , Dimmock David , Veeraraghavan Narayanan , Defay Thomas , Kingsmore Stephen F.
Published: April 2019

Automated phenotyping and interpretation of rapid whole-genome sequencing improve time to diagnosis of genetic diseases in hospitalized children.
Defects in Efflux (
oprM
), β-Lactamase (
ampC
), and Lipopolysaccharide Transport (
lptE
) Genes Mediate Antibiotic Hypersusceptibility of
Pseudomonas aeruginosa
Strain Z61
Authors: Shen Xiaoyu , Johnson Nicole V. , Kreamer Naomi N. K. , Barnes S. Whitney , Walker John R. , Woods Angela L. , Six David A. , Dean C. R.
Published: April 2019

Antibiotic hypersensitive bacterial mutants (e.g.,
Escherichia coli
imp
) are used to investigate intrinsic resistance and are exploited in antibacterial discovery to track weak antibacterial activity of novel inhibitor compounds.
Pseudomonas aeruginosa
Z61 is one such drug-hypersusceptible strain generated by chemical mutagenesis, although the genetic basis for hypersusceptibility is not fully understood.