bluuebunny/crossref_metadata_2025 huggingface dataset:
How to effectively use and interpret the barium swallow: Current role in esophageal dysphagia
Authors: Sanagapalli Santosh , Plumb Andrew , Lord Reginald V. , Sweis Rami
Published: April 2023

Background

The barium swallow is a commonly performed investigation, though recent decades have seen major advances in other esophageal diagnostic modalities.

Purpose

The purpose of this review is to clarify the rationale for components of the barium swallow protocol, provide guidance on interpretation of findings, and describe the current role of the barium swallow in the diagnostic paradigm for esophageal dysphagia in relation to other esophageal investigations. The barium swallow protocol, interpretation, and reporting terminology are subjective and non‐standardized. Common reporting terminology and an approach to their interpretation are provided. A timed barium swallow (TBS) protocol provides more standardized assessment of esophageal emptying but does not evaluate peristalsis. Barium swallow may have higher sensitivity than endoscopy for detecting subtle strictures. Barium swallow has lower overall accuracy than high‐resolution manometry for diagnosing achalasia but can help secure the diagnosis in cases of equivocal manometry. TBS has an established role in objective assessment of therapeutic response in achalasia and helps identify the cause of symptom relapse. Barium swallow has a role in the evaluating manometric esophagogastric junction outflow obstruction, in some cases helping to identify where it represents an achalasia‐like syndrome. Barium swallow should be performed in dysphagia following bariatric or anti‐reflux surgery, to assess for both structural and functional postsurgical abnormality. Barium swallow remains a useful investigation in esophageal dysphagia, though its role has evolved due to advancements in other diagnostics. Current evidence‐based guidance regarding its strengths, weaknesses, and current role are described in this review.
The evolution of extant South American tropical biomes
Authors: Jaramillo Carlos
Published: April 2023

This review explores the evolution of extant South American tropical biomes, focusing on when and why they developed. Tropical vegetation experienced a radical transformation from being dominated by non‐angiosperms at the onset of the Cretaceous to full angiosperm dominance nowadays. Cretaceous tropical biomes do not have extant equivalents; lowland forests, dominated mainly by gymnosperms and ferns, lacked a closed canopy. This condition was radically transformed following the massive extinction event at the Cretaceous–Paleogene boundary. The extant lowland tropical rainforests first developed at the onset of the Cenozoic with a multistratified forest, an angiosperm‐dominated closed canopy, and the dominance of the main families of the tropics including legumes. Cenozoic rainforest diversity has increased during global warming and decreased during global cooling. Tropical dry forests emerged at least by the late Eocene, whereas other Neotropical biomes including tropical savannas, montane forests, páramo/puna, and xerophytic forest are much younger, greatly expanding during the late Neogene, probably at the onset of the Quaternary, at the expense of the rainforest.
Effect of Material and Pad Abrasion on Shear Bond Strength of 3D‐Printed Orthodontic Brackets
Authors: Hanson Megan S. , Ontiveros Joe C. , English Jeryl D. , Wirthlin John O. , Cozad Benjamin E. , Harrington Daniel A. , Kasper F. Kurtis
Published: April 2023

Objective

To investigate the effect of printing material and air abrasion of bracket pads on the shear bond strength of 3D‐printed plastic orthodontic brackets when bonded to the enamel of extracted human teeth.

Materials and Methods

Premolar brackets were 3D‐printed using the design of a commercially available plastic bracket in two biocompatible resins: Dental LT Resin and Dental SG Resin (n = 40/material). 3D‐printed brackets and commercially manufactured plastic brackets were divided into two groups (n = 20/group), one of which was air abraded. All brackets were bonded to extracted human premolars, and shear bond strength tests were performed. The failure types of each sample were classified using a 5‐category modified adhesive remnant index (ARI) scoring system.

Results

Bracket material and bracket pad surface treatment presented statistically significant effects for shear bond strengths, and a significant interaction effect between bracket material and bracket pad surface treatment was observed. The non‐air abraded (NAA) SG group (8.87 ± 0.64 MPa) had a statistically significantly lower shear bond strength than the air abraded (AA) SG group (12.09 ± 1.23 MPa). In the manufactured brackets and LT Resin groups, the NAA and AA groups were not statistically significantly different within each resin. A significant effect of bracket material and bracket pad surface treatment on ARI score was observed, but no significant interaction effect between bracket material and pad treatment was found.

Conclusion

3D‐printed orthodontic brackets presented clinically sufficient shear bond strengths both with and without AA prior to bonding. The effect of bracket pad AA on shear bond strength depends on the bracket material.
The effect of a non‐congregate, integrated care shelter on health: A qualitative study
Authors: Alexander Karen , Nordeck Courtney D. , Rosecrans Amanda , Harris Robert , Collins Alexander , Gryczynski Jan
Published: April 2023

Objective

To describe the experiences of unstably housed, medically vulnerable residents living at the Haven, a novel, non‐congregate integrated care shelter operating in a historic hotel during the COVID‐19 pandemic.

Design

A qualitative descriptive design.

Sample/Measurement

Semi‐structured qualitative interviews were conducted in February and March 2022 with a purposive sample of 20 residents living in the integrated care shelter. Data were analyzed in May and June 2022 using the thematic analysis methods described by Braun and Clarke.

Results

Six women and 14 men, ages 23–71 (M = 50, SD = 14), were interviewed. Lengths of stay at the time of the interview ranged from 74 to 536 days (M = 311 days). Medical co‐morbidities and substance use details were collected at baseline. Three themes were identified: (1) Autonomy, (2) supportive environments, and (3) stability and the need for permanent housing. Participants characterized the integrated care, non‐congregate model as having multiple advantages over traditional shelter systems. Participants emphasized the role of nurses and case managers in providing a respectful, caring environment in the integrated shelter model.

Conclusion

Participants described acute physical and mental health needs which were largely met by the innovative integrated shelter care model. The effect of homelessness and housing insecurity on health is well documented, but few solutions exist that promote autonomy. Participants in this qualitative study emphasized the benefits of living in a non‐congregate integrated care shelter and the services which promoted their self‐management of chronic diseases.

Patient or Public Contribution

Patients were the participants in the study, but were not involved in the design, analysis of interpretation of the data, or preparation of the manuscript. Due to this project's small scope, we could not involve patients or the public after the study concluded data collection.
Equitable distribution of perishable items in a food bank supply chain
Authors: Sengul Orgut Irem , Lodree Emmett J.
Published: April 2023

In the United States, food banks play an important role in helping to reduce the rate of food insecurity by distributing donated food among the population in need. One of the challenges that food banks face is to equitably distribute food donations among their clients such that, ideally, each recipient receives the same amount of food. They aim to do so while minimizing waste that occurs due to spoilage and capacity limitations. Perishable food items present specific challenges since they are susceptible to spoilage and need to be distributed before their expiry dates. Based on our longstanding partnership with a large food bank located in the southeastern United States, we present a capacitated, multiperiod, multiproduct network flow model to help them equitably and effectively distribute perishable food donations among the food‐insecure population in their service region. The model is applied within the context of a case study and reveals managerial insights that would be useful to practitioners. Our findings show that although equity is one of the food bank's highest priorities, inequities cannot be eliminated completely. Given the inevitability of inequitable food allocations in practice, this paper provides food banks guidance on how to strategically control inequities using two approaches: ( i) by increasing the number of periods for which equity should be satisfied or ([Formula: see text]) by allowing deviations from a perfectly equitable distribution. The results show that modest deviations from perfect equity using either approach can lead to significant improvements in both the quality and quantity of food distributed and can also reduce food waste. While approach ([Formula: see text]) is preferable, the most desirable outcomes occur when both are applied simultaneously. We also find that county capacities inhibit a food bank's ability to achieve balance between equity and effectiveness when distributing perishables. Our framework provides food banks the flexibility to balance the trade‐off between effectiveness and equity based on their preferences.
Kul'turnost' Meets Kultur: Lyusya’s Testimony on Russian‐German Sexual Relations in Occupied Smolensk
Authors: David‐Fox Michael
Published: April 2023

This article examines German racial colonization in the occupied city of Smolensk in 1941–43 as a coerced but no less profound Nazi German‐Soviet Russian cross‐cultural encounter. Perhaps no other aspect of it was as fraught and taboo as the extensive sexual relationships between German men and Russian women. Liudmila Madziuk, known as Lyusya, was a member of the Komsomol underground whose testimony assumes special significance because of her political work among German soldiers. Her extraordinary accounts centered on the key Stalin‐era concept of kul'turnost' (culturedness), which in her hands competed with the ideological‐cultural claim to domination in the racialized Nazi version of the German key concept of Kultur. Her accounts are the kind of qualitative, first‐person sources that have been lacking as historians grapple with issues of sexuality, sexual barter, prostitution, rampant sexual violence, and the clash of the German and Soviet gender orders on the Eastern front. Lyusya and other young women of the 1930s generation glossed kul'turnost' in light of their own youthful, socialist, and feminist ambitions, implicitly counterposing it to the barbaric, backward‐looking brutality of Kultur. But what they assumed to be the bedrock of the communist world‐view and Soviet culturedness was shifting rapidly beneath their feet.
The novel HLA‐DRB1*14:251 allele, identified by Sanger dideoxy nucleotide sequencing in a Chinese individual
Authors: Hao Cai‐xia , Zheng Zhong‐zheng , Du Ke‐ming , An Lin , Yang Li‐jie
Published: April 2023

HLA‐DRB1*14:251 differs from HLA‐DRB1*14:126:01 by one nucleotide in exon 2.
Energy Subsidies and Social Public Expenditures in Emerging and Developing Countries
Authors: Nestor BRITON Bi Guessan , BALLO Zié
Published: April 2023

This article examines the effect of energy subsidies on social public expenditures for a sample of 57 emerging and developing countries over the period 2004-2019. The results of the system-based GMM approach reveal that energy subsidies negatively and significantly influence social public expenditures in the full panel, the poor, and resource-rich countries in our sample. These results confirm a political implication that consists in rationalizing energy subsidies in order to raise funds to support social public expenditures in emerging and developing countries.
Influence of Diffusion Bonding Pressure on Microstructural Features and Strength Performance of Dissimilar Ti–6Al–4V Alloy and AISI 304 Steel Joints Developed Using Copper Interlayer
Authors: Arun Negemiya A. , Rajakumar Selvarajan , Sonar Tushar , Ivanov Mikhail
Published: April 2023

The joining of Ti–6Al–4V (Ti64) alloy and AISI 304 austenitic stainless steel (ASS 304) carries significant importance in aeroengines for turbine blade applications. However, it is difficult to join using fusion welding. The fusion welding of Ti64 alloy and ASS 304 steel promotes the evolution of various Fe–Cr–Ti and Fe–Ti intermetallics in weld zone owing to limited solid solubility of Fe, Cr, Ti, and Ni with each other. The evolution of these intermetallics deteriorates the strength performance of joints. Hence for joining Ti64 alloy and ASS 304 steel, vacuum diffusion bonding (VDB) method is employed with thin copper (Cu) foil as an interlayer. The DB pressure extends significant influence on microstructural evolution and strength of joints. So, for the feasibility of joining Ti64 alloy and ASS 304 steel, the effect of DB pressure on microstructure and strength of joints is investigated. Results showed that the dissimilar joints of Ti64 alloy and ASS 304 steel developed using the DB pressure of 14 MPa exhibited greater lap shear strength (LSS) and bonding strength (BS) of 180 MPa and 268 MPa, respectively. It is attributed to the improved coalescence of joining interface and the development of ideal bonding width with the least amount of embrittlement consequences. An increase in DB pressure increases the width of the diffusion region which promotes the development of detrimental intermetallics of Ti–Fe and deteriorates the strength of dissimilar joints.
Using metal precursors to passivate oxides for area selective deposition
Authors: Canova Kinsey L. , Souqui Laurent , Girolami Gregory S. , Abelson John R.
Published: April 2023

Although it has long been known that metal-containing compounds can serve as catalysts for chemical vapor deposition (CVD) of films from other precursors, we show that metal-containing compounds can also inhibit CVD nucleation or growth. For two precursors A and B with growth onset temperatures TgA < TgB when used independently, it is possible that B can inhibit growth from A when the two precursors are coflowed onto a substrate at a temperature (T) where TgA < T < TgB. Here, we consider three precursors: AlH3⋅NMe3 (Tg = 130 °C, Me = CH3), Hf(BH4)4 (Tg = 170 °C), and AlMe3 (Tg = 300 °C). We find that (i) nucleation of Al from AlH3⋅NMe3 is inhibited by Hf(BH4)4 at 150 °C on two oxide surfaces (Si with native oxide and borosilicate glass), (ii) nucleation and growth of HfB2 is inhibited by AlMe3 at 250 °C on native oxide substrates and on HfB2 nuclei, and (iii) nucleation of Al from AlH3⋅NMe3 is inhibited by AlMe3 at 200 °C on native oxide substrates. Inhibition by Hf(BH4)4 is transient and persists only as long as its coflow is maintained; in contrast, AlMe3 inhibition of HfB2 growth is more permanent and continues after coflow is halted. As a result of nucleation inhibition, AlMe3 coflow enhances selectivity for HfB2 deposition on Au (growth) over Al2O3 (nongrowth) surfaces, and Hf(BH4)4 coflow makes it possible to deposit Al on Al nuclei and not on the surrounding oxide substrate. We propose the following criteria to identify candidate molecules for other precursor–inhibitor combinations: (i) the potential inhibitor should have a higher Tg than the desired film precursor, (ii) the potential inhibitor should be unreactive toward the desired film precursor, and (iii) at the desired growth temperature, the potential inhibitor should adsorb strongly enough to form a saturated monolayer on the intended nongrowth surface at accessible inhibitor pressures.
Nanostructured MoS2 thin films: Effect of substrate temperature on microstructure, optical, and electrical properties
Authors: Alev Onur , Goldenberg Eda
Published: April 2023

Molybdenum disulfide (MoS2), a two-dimensional transition-metal dichalcogenide, has the potential for applications in next-generation optoelectronic devices. In this work, MoS2 thin films were deposited by using radio frequency magnetron sputtering on glass and silicon substrates at different substrate temperatures. The effect of growth temperature on crystalline structure, morphology, compositional, optical, and electrical properties of MoS2 thin films was systematically evaluated. It is observed that surface morphology depended on the substrate temperature. Nanowormlike structures formed at the surface of films deposited at 100 and 200 °C. Raman analysis indicated that the mode separation distance for films deposited at room temperature was close to 25 cm−1 of the bulk value. However, mode separation was higher than 27 cm−1 when the substrate temperature was high. This can be attributed to sulfur vacancy in the MoS2 lattice and to strain formation. The bandgap of thin films was estimated to be in the range of 2.3–2.8 eV. X-ray photoelectron spectroscopy was used to investigate chemical composition as well as the effect of the substrate temperature on sulfur vacancies in films. Mo(IV)/S ratios were found to be 1.29, 1.94, and 1.87 for substrate temperatures of RT, 100 °C, and 200 °C, respectively. The conductivity of MoS2 thin films varied considerably with the substrate temperature during deposition. The highest conductivity, 10−13 S/cm, was observed at 300 K measurement temperature in films deposited at room temperature.
Transport and trap states in proton irradiated ultra-thick κ-Ga2O3
Authors: Polyakov A. Y. , Nikolaev V. I. , Pechnikov A. I. , Yakimov E. B. , Lagov P. B. , Shchemerov I. V. , Vasilev A. A. , Kochkova A. I. , Chernykh A. V. , Lee In-Hwan , Pearton S. J.
Published: April 2023

Changes induced by irradiation with 1.1 MeV protons in the transport properties and deep trap spectra of thick (>80 μm) undoped κ-Ga2O3 layers grown on sapphire are reported. Prior to irradiation, the films had a donor concentration of ∼1015 cm−3, with the two dominant donors having ionization energies of 0.25 and 0.15 eV, respectively. The main electron traps were located at Ec−0.7 eV. Deep acceptor spectra measured by capacitance-voltage profiling under illumination showed optical ionization thresholds near 2, 2.8, and 3.4 eV. The diffusion length of nonequilibrium charge carriers for ɛ-Ga2O3 was 70 ± 5 nm prior to irradiation. After irradiation with 1.1 MeV protons to a fluence of 1014 cm−2, there was total depletion of mobile charge carriers in the top 4.5 μm of the film, close to the estimated proton range. The carrier removal rate was 10–20 cm−1, a factor of 5–10 lower than in β-Ga2O3, while the concentration of deep acceptors in the lower half of the bandgap and the diffusion length showed no significant change.
Nonlinear features in whistles produced by the short-beaked common dolphin (Delphinus delphis) off southeastern Brazil
Authors: Figueiredo Luciana Duarte de , Maciel Israel , Viola Flavio M. , Savi Marcelo A. , Simão Sheila M.
Published: April 2023

Animal vocalizations have nonlinear characteristics responsible for features such as subharmonics, frequency jumps, biphonation, and deterministic chaos. This study describes the whistle repertoire of a short-beaked common dolphin (Delphinus delphis) group at Brazilian coast and quantifies the nonlinear features of these whistles. Dolphins were recorded for a total of 67 min around Cabo Frio, Brazil. We identify 10 basic categories of whistle, with 75 different types, classified according to their contour shape. Most (45) of these 75 types had not been reported previously for the species. The duration of the whistles ranged from 0.04 to 3.67 s, with frequencies of 3.05–29.75 kHz. Overall, the whistle repertoire presented here has one of the widest frequency ranges and greatest level of frequency modulation recorded in any study of D. delphis. All the nonlinear features sought during the study were confirmed, with at least one feature occurring in 38.4% of the whistles. The frequency jump was the most common feature (29.75% of the whistles) and the nonlinear time series analyses confirmed the deterministic chaos in the chaotic-like segments. These results indicate that nonlinearities are a relevant characteristic of these whistles, and that are important in acoustic communication.
The Rayleigh mode at the plane boundary between a liquid and a double porosity medium
Authors: Kachkouch Fatima Zahraa , Franklin Hervé
Published: April 2023

The Rayleigh mode (also called generalized Rayleigh wave) at the flat interface between a liquid and a double porosity medium saturated by the same liquid, is investigated. The double porosity medium obeys the phenomenological model of Berryman and Wang (2000). It allows the simultaneous propagation of three longitudinal waves and a transverse wave. Assuming open pore conditions at the interface, formulas are found for the coefficients of reflection in the liquid and of transmission in the double porosity medium. Considering only the angular variable in the study, numerical simulations based on data for Berea sandstone show the influence of frequency and the two types of porosity on the reflection coefficient and on the velocity of the generalized Rayleigh wave.
Convolutional neural network with data augmentation for object classification in automotive ultrasonic sensing
Authors: Eisele Jona , Gerlach André , Maeder Marcus , Marburg Steffen
Published: April 2023

Today's low-cost automotive ultrasonic sensors perform distance measurements of obstacles within the close range of vehicles. For future parking assist systems and autonomous driving applications, the performance of the sensors should be further increased. This paper examines the processing of sensor data for the classification of different object classes and traversability of obstacles using a single ultrasonic sensor. The acquisition of raw time signals, transformation into time-frequency images, and classification using machine learning methods are described. Stationary and dynamic measurements at a velocity of 0.5 m/s of various objects have been carried out in a semi-anechoic chamber and on an asphalt parking space. We propose a scalogram-based signal processing chain and a convolutional neural network, which outperforms a LeNet-5-like baseline. Additionally, several methods for offline and online data augmentation are presented and evaluated. It is shown that carefully selected augmentation methods are useful to train more robust models. Accuracies of 90.1% are achieved for the classification of seven object classes in the laboratory and 66.4% in the outdoor environment. Traversability is correctly classified at an accuracy of 96.4% and 91.5%, respectively.
The verasonics platform for ultrasound-guided focused ultrasound preclinical studies
Authors: Kaczkowski Peter , Ormachea Juvenal
Published: April 2023

Verasonics, in partnership with Sonic Concepts (Bothell, WA, USA), has developed a turnkey platform for Ultrasound-Guided Focused Ultrasound (USgFUS) therapy with performance over a wide range of acoustic regimes. Built around the Verasonics Vantage HIFU ultrasound research system, it uses a 150 mm diameter, f1 HIFU transducer with 64 (0.5 MHz) or 128 (1.1 and 2 MHz) elements arranged in a spiral pattern that produce a highly focused field with low sidelobes over a 3D steering volume. Guidance and monitoring are provided by a coaxially mounted 128-element broadband phased array imaging transducer that can be rotated about the HIFU axis. Coupling to the subject is achieved by means of a membrane sealed water-filled cone through which degassed and temperature regulated water is circulated. The USgFUS applicator is mounted on an articulated arm that can be mechanically locked with a button actuated servo mechanism. Graphical software enables a conventional therapeutic workflow including imaging with any of several B-Mode and Doppler modalities, positioning of the applicator, focal zone exposure planning, therapy delivery, interleaved ultrasound monitoring using any supplied imaging mode or with Thermal Strain Imaging (TSI), and post-therapy imaging. This talk will describe the platform and provide examples of its capabilities using experiments in scattering phantoms and ex vivo tissues.
Real-time co-location in dynamic virtual soundscapes across multi-occupant immersive rooms
Authors: Huang Mincong , Chabot Samuel , Braasch Jonas
Published: April 2023

Immersive rooms, a type of virtual reality system consisting of human-scale panoramic visual and acoustic display systems and distributed sensing apparatus for occupant motion, have been increasingly adopted for dynamic and interactive applications. While these applications enable multi-user audiovisual immersion and navigation from a single physical location, they have yet to propagate along multiple homogeneous system infrastructures in a networked manner. In this work, we intend to co-locate two physically-remote immersive rooms – at EMPAC and the CRAIVE-Lab, respectively – in a single system of shared environments developed in Unity and embedded with virtual soundscapes. This system actively monitors spatial properties of both immersive rooms’ dynamic virtual footprint and their corresponding occupants. It generates virtual sound sources. both procedurally and through spatially-aware user inputs. The sound sources are rendered in real time via an algorithm synthesizing a ray-traced early reflection window and a parameterized late reverberation estimate from in-scene geometries. The co-located virtual soundscapes, displayed in individual immersive rooms through their respective multi-channel wave field synthesis loudspeaker systems, are shared as such that the user interaction in one physical location has holistic effects on the experience of virtual environments across all associated physical locations. [Work supported by NSF IIS-1909229 & CNS-1229391.]
MEMS microphone arrays for quench detection in superconducting cables
Authors: White Robert D. , Beckett Aidan , Chaudhary Rishabh , Chiesa Luisa , Desai Amish , Doolittle Odin , Emerling Michael , Moore Peter , Takayasu Makoto , Zhang Boning
Published: April 2023

An acoustic array is proposed as a quench detection method in superconducting magnets. A quench occurs when the current density in the superconductor exceeds a critical value, resulting in a loss of superconductivity and rapid local heating. This event is destructive and must be rapidly detected. It is thought that the quench may act as an acoustic source (Takayasu, 2019), which could be detected and localized by a microphone array inserted into the cryogenic coolant. A main advantage of this method is that acoustics propagate 1000 times faster than the normal zone propagation velocity in HTS conductors, providing for fast detection times. To demonstrate this concept, we first characterized the performance of a piezoelectric MEMS microphone and several potential preamplifiers under cryogenic conditions. An acoustic sense node was then constructed that operates down to 10 K. A cryogenic probe incorporating the MEMS array was used to study a quench event in a segment of a 2 mm wide REBCO tape. Quench experiments were carried out in a 7.6 cm diameter, 111 cm tall cryostat in Helium gas at 20 to 50 K. The MEMS array clearly detects a quench induced failure. Other observed acoustic features of unknown origin will be described.
Simulation of multiphonic vocalization: How many sound sources can the lungs support simultaneously?
Authors: Titze Ingo R.
Published: April 2023

The hypothesis tested was that the lung pressure required for multiphonic vocal sound sources (some combinations of true folds, false folds, aryepiglottis folds, tongue base, velum, lips) is the sum of all the individual threshold pressures. The approach was strictly computational. Fluid transport and wave propagation in the airways were produced by an abbreviated Navier–Stokes solution. Each of the sound sources was modeled with three narrow 0.2 cm sections having viscous and elastic wall properties that could oscillate in isolation. The length of the supraglottal vocal tract was 17.5 cm. The simulation was used to compute phonation threshold pressure, radiated power from the mouth, degree of aperiodicity, and glottal efficiency.
Electronic architecture—Improving room acoustics using time variant electro-acoustic systems
Authors: Barbar Steve
Published: April 2023

In 1990, we presented a technical paper at the Audio Engineering Society that described a new and unique system that enables microphones to be positioned as much as 50 feet from the sound source while producing high reverberation level without coloration from acoustic feedback. Since that time, hundreds of these systems have been installed throughout the world in both a wide range of applications, as well as wide variety of venues. We will discuss successful solutions for acoustical problems that are difficult to address using conventional architecture.
Measurements of ship noise using an acoustic camera: A first survey
Authors: Bocanegra Johan A. , Borelli Davide , Schenone Corrado
Published: April 2023

While the acoustic impact of harbours is becoming an increasingly important issue, to the point of limiting their growth, the measurement of noise from ships and port operations is still rough. Two of the main problems that are commonly encountered are source overlapping and large distance from the emitting sources. Source overlapping prevents from identifying the specific contribution coming from each acoustic source. The large distance from the emitting sources, for instance the funnel of a ship or the engine of a transtainer crane, makes the measurement inaccurate. By using the acoustic camera it is possible to tackle these two problems at the same time. Noise measurements can be made with equipment far from noise source, while distinguishing the contribution from each single source emitting within the sound field. The paper demonstrates this enhanced measurement technique through a set of surveys performed inside French and Italian ports. The ship emissions are analyzed through the acoustic camera for ship on the way, maneuvering inside the harbour, and berthed at wharf. The effectiveness of beamforming technique is discussed, investigating the measurements accuracy, their qualitative and quantitative significance, and the possibility tointroduce specific measurement standards for ships based on this methodology.
Reflections on the physics of slow dynamics in rocks
Authors: TenCate James A.
Published: April 2023

Slow Dynamics is a peculiar property exhibited by many sedimentary rocks and was first reported in the mid 1990s. Slow dynamics refers to the process of changing the elastic state of a rock, softening its macroscopic stiffness with application of an AC acoustic drive. What makes slow dynamics unique is that the elastic state of the rock recovers as log(time) once the acoustic drive is turned off. Many creep-like mechanisms have been proposed to explain the effect, notably it resembles recoverable/reversible DC creep. The most common explanation is due to the effects of water, or a form of it, in the spaces between grains. However, it has been exceedingly difficult to pin down the real physics. One experiment with Berea sandstone at high vacuum and temperatures showed that slow dynamics still persists even at these conditions. Followup experiments are in progress, using a pure quartz Fontainebleau sandstone to avoid any effects of clays. Another experiment is planned which will mimic conditions on Mars where water in any form is of great interest to planetary geologists. [Work supported by the Office of Basic Sciences, DOE and by Laboratory Directed Research and Development funding.]
Slow dynamics in a single bead with mechanical conditioning and transient heating
Authors: Weaver Richard , Lee Sangmin
Published: April 2023

The ultrasonically-measured contact stiffness of an aluminum bead confined between two slabs diminishes on mechanical conditioning, and then recovers like log(t) after the conditioning ceases. Here that structure is evaluated for its response to transient heating and cooling, with and without accompanying conditioning vibrations. It is found that, under heating or cooling alone, stiffness changes are mostly consistent with temperature dependent material moduli; there is little or no slow dynamics. Hybrid tests in which vibration conditioning is followed by heating or cooling lead to recoveries that begin like log(t) and then become more complex. On subtracting the known response to heating or cooling alone we discern the influence of higher or lower temperatures on slow dynamic recovery from vibrations. It is found that heating accelerates the initial log(t) recovery, but by an amount more than predicted by an Arrhenius model of thermally activated barrier penetrations. Transient cooling has no discernable effect, in contrast to the Arrhenius prediction that it inhibits recovery. [Supported by the DOE, DE-SC0021056].
Dave Green and psychoacoustics
Authors: Yost William A.
Published: April 2023

Dave Green’s career spanned four decades all devoted to the study of psychoacoustics. It is hard to imagine anyone whose work has had a greater impact on the field. Dave’s interest in psychoacoustics began as an Experimental Psychology student at the University of Michigan. He is most widely recognized in the field of psychophysics for his pioneering contributions to Signal Detection Theory (SDT), which he helped develop in the Electronic Defense Group (EDG) of the Department of Electrical Engineering in the early 1950s. The culmination of this work is given in his seminal text “Signal Detection Theory and Psychophysics” (co-authored with John Swets) in 1966. His later work on Profile Analysis in the 1980s helped established a new view of auditory perception. As a consultant for Bolt, Beranek, and Newman (BB&N), Dave provided numerous publications and reports that have served beneficial to society, including his testimony regarding the reenactment of the assassination of John F. Kennedy in 1979. More than 50 students, post-docs, and colleagues, many who have made important contributions to psychoacoustics, have worked directly in Dave’s labs and received his mentoring. To say that Dave Green is a psychoacoustic icon would be an understatement.
The influence of temporal features of the signal on detectability: Data and signal-detection analyses
Authors: Wright Beverly A. , Dai Huanping
Published: April 2023

Dave Green had an enormous influence on auditory research via signal-detection theory. A major contribution of signal-detection theory is the concept and application of the ideal detector, which establishes the absolute optimal detection performance. To bridge between the ideal performance and the less-than-ideal human performance, Green and Swets (1966) described an energy detector. The energy-detector model relaxed assumptions of the ideal detector to account for the phase insensitivity and limited frequency selectivity of humans, but it retained the assumption that the time window is matched to the signal duration. However, the time-window assumption had no clear support from human data. To help fill this gap, we examined the detectability of signals with expected versus unexpected temporal properties. The results of experiments and signal-detection analyses suggest that listeners listen selectively to signal duration, implying that they match the time window to the overall signal duration as was assumed in the energy-detector model. Additional results suggest that listeners do not also listen selectively to the temporal structure of the signal, implying that the temporal constraint is based on overall signal duration. We are grateful for the opportunity to have worked with Dave.
Computational analysis of sub-wavelength scatterers exhibiting electro-momentum coupling
Authors: Wallen Samuel P. , Goldsberry Benjamin M. , Gokani Chirag A. , Haberman Michael R.
Published: April 2023

The macroscopic response of acoustic metamaterials with sub-wavelength asymmetry may be described by the so-called Willis constitutive relations, which include coupling between the acoustic pressure and momentum density. One method to describe the behavior of acoustically-small, Willis material building-blocks is via a polarizability matrix relating the monopole and dipole scattering moments to the local pressure and velocity fields, providing a metric for the design of microscale structures leading to macroscopically observable Willis coupling. Additionally, heterogeneous, piezoelectric media with sub-wavelength asymmetry have been shown to exhibit coupling between momentum density and electric fields, a material response known as electro-momentum coupling. Recent studies have generalized the polarizability concept to include coupling between acoustic and electromagnetic fields for theoretical point scatterers in two and three dimensions, and derived analytical bounds based on conservation of energy. In this work, we computationally study the coupled, acousto-electromagnetic polarizability of heterogeneous, piezoelectric scatterers and assess the practicability of achieving electro-momentum coupling in physically realizable geometries. Numerical results are obtained using a custom finite element approach, which includes the fully electrodynamic nature of the system and accounts for large differences in the characteristic wavelengths of the acoustic and electromagnetic fields. [This work was supported by DARPA.]
Dual-task costs of clear and loud speech: Implications for talkers with Parkinson disease
Authors: Whitfield Jason A.
Published: April 2023

Decades of research suggest that the speech production adjustments associated with adopting a clearer or louder speaking style enhance speech intelligibility, making these speech styles a common talker-oriented strategy in speech production interventions for talkers with dysarthria secondary to Parkinson disease (PD). Recent data suggest that explicit instructions to speak louder or clearer than usual may increase the processing load and effort associated with speech production. Empirical data will be presented that demonstrate these higher-effort speech styles may require greater attentional resources than habitual or conversational speech. A group of neurotypical talkers performed a sentence repetition task using Habitual, Loud, and Clear speech styles in isolation and while performing a concurrent visuomotor tracking task. Lip and jaw kinematics, speech intensity, and accuracy on the visuomotor task were collected to quantify performance on each task. Group-level data suggest that when faced with the competing task demands of the visuomotor task, neurotypical talkers prioritized the articulatory and phonatory adjustments associated with Clear and Loud speech at the cost of secondary task performance. Case examples from talkers with hypokinetic dysarthria resulting from PD will also be examined to frame and discuss clinical implications and considerations.
Sound and voice information transfer enhancement of OLED TV in OTT environment
Authors: Park Hyungwoo , Lee Sungtae
Published: April 2023

People get a lot of information around them through visual, auditory, and various senses. In particular, audiovisual data is a very important information transfer factor and has developed various technologies and methods for a long time . In previous studies, we have found that a better effect is achieved when the focus of the screen matches the focus of the sound. To that end, it is now possible to create a sound by vibrating a modern display panel, such as an OLED (Organic Light-Emitting Diode). In our previous research, we have studied the research of creating a stereo sound by directly vibrating a single plane, the reason why the sound of this method is better than the ordinary audio system, the position of the exciter optimized for sound quality, the shape of the exciter and the enclosure of speakers. In this study, a research was conducted on the understanding of the audience's voice by the sound composition in an over the top (OTT) environment that supplies a lot of content recently. In the OTT environment, we try to provide picture quality and sound similar to that of a theater. However, the traditional audio method rather lowers the ability to transmit information of voice. The sound system using the proposed sound radiation system overcomes this problem and creates a clear voice, thereby solving the viewer's discomfort with the sound.
An experimental study of acoustical design, physiological measurements, and repetitive behaviors in children with autism
Authors: Kanakri Shireen
Published: April 2023

Researchers have known that sound is an aspect of the environment that can have an effect on children with Autism Spectrum Disorder (ASD) due to hypo or hypersensitivities that are commonly present in this population. What is less known is how sound is specifically correlated to behaviors and physiological phenomenon. In order to build a predictive measure of sound decibel level on behavior, children with ASD were observed in a controlled environment while exposed to varying acoustic levels. Behaviors, heart rate, ECG, and respiration were recorded during experimental sessions and results revealed that the children typically stayed on task consistently throughout the sound stimulation; however, significant ECG, HR, and respiration rate variances occurred at the different sound levels in all behaviors. The results found from this study do point to a predictive relationship when it comes to the influence of sound and physiological readings on behavior in ASD children.
Auditory processing for action selection in bats
Authors: Salles Angeles , Loscalzo Emely , Montoya Jessica , Boergens Kevin , Moss Cynthia F.
Published: April 2023

Bats are auditory specialists, processing acoustic signals to guide their behaviors, including prey tracking, navigation and communication. In this talk I will provide an overview of my work related to how bats analyze and process signals for action-selection; specifically prey tracking and background clutter segregation—work inspired by research from Jim Simmons’s lab. I will also give an overview of the line of research of my current lab, neural mechanisms for auditory processing of communication signals. There is strong evidence that context plays a role in the processing of acoustic signals. Yet, the mechanisms that govern this process are still not fully understood. Eptesicus fuscus bats emit a wide array of communication calls, including food claiming calls, aggressive calls and appeasement calls. We developed a novel competitive foraging task to explore the role of behavioral context in auditory responses to social calls. With this approach, we recorded neural population responses from the IC of freely interacting bats. Analysis of our neural recordings from the IC show stronger population responses to individual calls during behaviorally aggressive events. These results indicate that behavioral context plays a role in the modulation of neuronal population responses to social vocalizations in the bat IC.
Hypertensive disorders of pregnancy and echocardiography in cardio-obstetrics
Authors: Countouris Malamo
Published: April 2023

Hypertensive disorders of pregnancy, such as preeclampsia, are associated with adverse cardiovascular outcomes in the peripartum period including heart failure, peripartum cardiomyopathy, and stroke. Echocardiography provides a noninvasive way to assess cardiac structure and function and changes related to hypertensive disorders of pregnancy. In this talk, we will discuss expected cardiac changes measured by echocardiography among women with hypertensive disorders of pregnancy. We will also discuss other cardiac complications related to pregnancy (such as spontaneous coronary artery dissection and peripartum cardiomyopathy) and associated echocardiographic findings. Finally, we will discuss later life echocardiographic findings among individuals with prior hypertensive disorders of pregnancy.
Sonoreperfusion with fibrin-targeted phase shift microbubbles for the treatment of microvascular obstruction
Authors: Mohammed Soheb Anwar , Amjad Muhammad Wahab , Chen Xucai , Acosta Maria F. , Hanrahan Dillion , Meuillet Emmanuelle J. , Unger Evan C. , Pacella John J.
Published: April 2023

More than 1 million Americans yearly have a new or recurrent acute myocardial infarction (AMI). Although the mortality rate from AMI has decreased in recent years, post-MI congestive heart failure is increasing due to microvascular obstruction (MVO), ultimately limiting myocardial salvage. We aim to address this unmet need by devising an image-guided therapy called sonoreperfusion (SRP) to resolve MVO by ultrasound-targeted microbubble cavitation (UTMC). In this study, we hypothesized that fibrin-targeted phase shift microbubbles (FTPSMBs; ∼200 nm) (Microvascular Therapeutics, Inc) would improve SRP efficacy compared to fibrin-targeted microbubbles (FTMBs; 1–3 μm) to treat MVO owing to the smaller size and more efficient microthrombi penetration. A rat hindlimb model of MVO was created by directly injecting freshly prepared porcine microthrombi into the left femoral artery under contrast-enhanced ultrasound imaging (CEUS) guidance, and treated with UTMC (1 MHz, 1.5 MPa, 5 ms pulse duration, 5-sec pulse interval) with concomitant administration of FTPSMBs/FTMBs (3 mL/hr). The treatment effect was accessed with CEUS. UTMC with FTPSMBs caused more rapid and complete reperfusion of rat hindlimb following MVO compared with FTMB, likely owing to their small size and more effective thrombus penetration. Studies to explore the underlying molecular mechanisms associated with SRP treatments are underway.
Mitigating wind noise in multichannel active noise control systems
Authors: Zhao Sipei , Chu Yijing
Published: April 2023

Multichannel active noise control (ANC) systems have been investigated to reduce outdoor low-frequency noise, such as power transformer noise and traffic noise. However, in outdoor environments, wind noise is inevitable and significantly degrades the noise reduction performance of active control systems. Despite broad adoption in windy environments, porous microphone windscreens cannot eliminate low-frequency wind noise in microphones, especially when the wind speed is high. Assuming wind noise is additive and uncorrelated with the primary noise to be controlled, this paper analyses how the wind noise detected by the reference microphone impacts the control filters and the residual noise of a multichannel ANC system based on the multichannel filtered-reference least mean squares algorithm (MFxLMS). By extending our recent research on wind noise suppression in single-channel active noise control systems [Y. Chu, et al., J. Acoust. Soc. Am. 152(6), 3340–3345 (2022)], a modified MFxLMS algorithm based on a new cost function is proposed. Simulations with real-recorded wind noise are performed to verify the theoretical analysis.