bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel and computationally efficient subgrid technique for modeling scattering and Doppler effects of rough dynamic sea surfaces using the finite-difference time-domain method
Authors: Higgins Alex , Siderius Martin
Published: November 2023

Over the last decade, the improvements in computational performance that multiprocessing, solid-state hard drives, and fast memories have brought to desktop workstations have made modeling and simulation methods that were previously inaccessible into the office workspace. These methods were previously restricted to large servers or computer clusters because of their demanding computation and large memory requirements when applied to underwater acoustic simulation scenarios. One such method is the Finite-difference Time-domain (FDTD) technique. The FDTD method is a discrete numeric model that provides the full pressure wave solution solved directly in the time domain. This makes it an ideal model for investigating scattering and Doppler effects of boundaries with complex geometries and motion. A fully developed sea surface generated using the Pierson–Moskowitz wavenumber spectra meets these criteria. A novel subgrid technique has been developed to improve the accuracy of signals scattered from fully developed sea surfaces. This method remains computationally efficient because the subgrid is applied only along the rough sea surface as it varies over time. The FDTD subgrid method has been applied to simulations that investigate the “frozen” sea surface assumption that is utilized by other traditional models that incorporate boundary motion.
Physical aspects of live clarinet performances
Authors: Almeida Andre , Li Weicong , Wolfe Joseph , Smith John , Schubert Emery
Published: November 2023

The clarinet is arguably the wind instrument that has been most extensively studied and described from the point of view of its physics. It has a relatively simple geometry, its embouchure can be fairly well approximated by a set of two control variables, and the air column can be accessed relatively easily, allowing for the measurement of control variables and acoustic variables close to the mouthpiece. As a result, extensive datasets have been collected, allowing understanding of how the sound produced by the instrument changes as a function of its control parameters. In this presentation, we explore a new dataset of control variables (mean reed displacement, blowing pressure, bite position, and others) and acoustic variables (sound level, pitch, spectral centroid, and others) recorded in performances on the clarinet by expert players. These data are compared with measurements and modeling of the instrument blown in mechanical conditions.
Acoustic characterization of an installed elliptical jet
Authors: Beekman Jayson R. , Weightman Joel , Nogueira Petronio , Jordan Peter , Edgington-Mitchell Daniel
Published: November 2023

This work demonstrates a preliminary acoustic characterization of an installed elliptical jet with an aspect ratio of 2. This configuration is compared against the nominal axisymmetric installed jet case of equivalent diameter. A baseline case for the elliptical and axisymmetric nozzle geometries are obtained in the uninstalled configuration. For all cases, the acoustic Mach number is varied between 0.4 and 1.0, the azimuthal observer angle between 0° and 90°, and the axial distance from the jet exit to the observer between 0 and 30 nozzle equivalent diameters. The latter of these is an analogue for polar angle variation by keeping the radial distance from the jet to the observer constant. A flat metal plate is used for the installed case, creating a jet–plate interaction mimicking that of an aircraft engine’s exhaust and its wing. Using the same variations as the free jet, parameters such as plate height, trailing-edge distance and, for the elliptical jet, nozzle exit rotation angle are investigated to give a broad characterization of the installed elliptical jet and enable direct comparison to the axisymmetric jet case. The key comparison metric for this work is the overall sound pressure level and polar directivity of the acoustic fields.
Development and evaluation of laser acoustic measurement system for supersonic jet noise
Authors: Matsumoto Kazuki , Kwon Youngha , Okamoto Koji , Akamine Masahito , Teramoto Susumu
Published: November 2023

Acoustic measurements in the near field are significant to suppress the noise generated by a supersonic jet. The microphone measurement is commonly used to measure noise, but it is not appropriate for the jet noise measurement in the near field, because it may be broken or disturb the sound field. In this study, we propose an optical acoustic measurement method using a laser and a 2-D position sensitive detector. This system can measure the propagating direction and the spectra of acoustic waves by detecting the angle and direction of laser path deflection by acoustic wave passing. To evaluate this laser measurement method, it was applied to various supersonic jet noise phenomena, such as Mach waves and screech tones, and then the results were compared with those of microphone measurements. The spectra measured by the laser measurement show good agreement with those by microphone measurements, and the difference in OASPL was less than 0.7 dB. As for the propagating direction, it is calculated using the principal component analysis in the laser measurement, and its results also show good agreement with those of acoustic intensity vector measurement.
An investigation of shock cell-related noise in an installed, full-scale tactical jet engine using acoustical holography
Authors: Mathews Logan T. , Gee Kent L.
Published: November 2023

Shock cells in imperfectly expanded supersonic jet flows have been found to contribute to the noise radiated by these jets. Acoustic phenomena such as screech and broadband shock-associated noise have been linked to the shock cell structure in jets. Acoustical holography has been used to study various jet noise source and radiation characteristics. Holography-based reconstructions near the acoustic source in an installed, full-scale tactical jet engine have yielded features indicative of the known shock cell structure in the jet. This paper presents these results and investigates the characteristics of these features, including their distribution and relative amplitudes.
Is an exceedance always a non-compliance?
Authors: Clark Laurence
Published: November 2023

Consider a typical scenario taking place across NSW every day: construction on a major infrastructure project. The contractor has previously assessed the noise impact in a report as required by Regulators. But theactual noise levels exceed the levels in their report. Are they “non-compliant”?Yes, for respite nights when construction noise must not exceed Noise Management Levels (NMLs). By contrast, NMLs can be exceeded on “noisy” nights, but all feasible and reasonable noise mitigation measures must be applied. What is reasonable is related to the predicted level of construction noise—there is an expectation in the community and by regulators that the higher the predicted noise level, the more reasonable it is to implement additional feasible noise mitigation measures. Performance is usually evaluated by monitoring. Monitored noise levels that exceed NMLs, or predicted levels, usually called “exceedances,” can be considered to be non-compliances on “noisy” nights. This approach has some undesirable outcomes, such as encouraging overprediction. A better approach might be to require an evaluation into the reasons why a monitored level is greater than a predicted level, followed by the application of appropriate corrective action. A non-compliance would then only occur if this does not take place.
Comparison of predictions from web-based construction noise tool with operator-attended field measurements
Authors: Morris Adrian , Tabacchi Mattia , Zhafranata Raihan
Published: November 2023

Web-based noise prediction tools are increasingly being used to assist infrastructure projects in Australia with managing construction noise impacts. Typically, these noise tools use a pre-calculated set of noise predictions from a detailed 3-D computer noise model, with the web app providing an interface for the user to select (manually or automatically) the most appropriate reference source and adjusting the result to align with the desired sound power level. Verification noise monitoring is often prescribed as a management measure, particularly when the noise predictions exceed the nominated target at one or more noise-sensitive receivers. These noise measurements are then used to determine if corrective actions are necessary. An analysis of predicted levels generated using Gatewave and subsequent verification noise measurements has been conducted, with consideration given to key parameters such as plant/equipment and measurement locations and equipment sound power levels. Identification of key causes for deviations between predicted and measured levels is also discussed.
Noncontact rotation of a small object using an asymmetric ultrasonic field
Authors: Yamamoto Eimei , Koyama Daisuke
Published: November 2023

Noncontact manipulation techniques using airborne high-intensity ultrasound can be applied in various industrial fields such as pharmaceutical industry and future space industry. This paper discusses a method to rotate a small object in the air without physical contact using ultrasound. The experimental system consists of a vibrating disc with four bolt-clamped Langevin-type ultrasound transducers and two semicircular reflectors. The flexural vibration of the disc generates an acoustic standing wave between them, and a small object can be levitated at the nodal position. By inclining one of the two reflectors, an asymmetric acoustic field and an acoustic traveling wave in the circumferential direction are generated where the object can be rotated in the clockwise or counterclockwise direction. Vector flows of the acoustic intensity in the air between the vibrator and reflectors were calculated. When the tilt angle of the reflector was 0.32°, the object was rotated without contact, and the rotation direction corresponded with the direction of the vector flows of the acoustic intensity. A greater input current gave a greater rotation speed; the maximum rotation speed of the object was 6.84 rps in the case of 1.14 A.
Subcortical measures of multi-talker speech processing
Authors: Polonenko Melissa , DiNino Mishaela , Maddox Ross
Published: November 2023

Communication in everyday acoustic environments is facilitated by the ability to locate, separate, and process speech from different locations. We do this by combining information received by both ears. Typically, the auditory system does not simply relay information delivered by both ears; rather, bilateral information is combined through elaborate binaural pathways in both the brainstem and cortex to allow us to communicate in complex acoustic environments. But traditionally it has been difficult to evaluate the subcortical underpinnings of speech communication using more complex, naturalistic continuous speech stimuli. Recently, the “peaky” speech method was created that uses stories to evoke brainstem responses using EEG. We have recorded brainstem responses from adults with normal hearing who listen to one or multiple narrators, and narrators coming from one or different perceived spatial locations. This talk will highlight the brainstem work undertaken towards creating subcortical measures of speech processing and spatial hearing.
Temporal dynamics of the medial olivocochlear reflex in humans
Authors: Mishra Srikanta k.
Published: November 2023

Ipsilateral and contralateral sounds can activate the medial olivocochlear reflex. The time course of medial efferent effects could contribute to the binaural unmasking of sounds. Computational modeling suggests that implementing efferent time constants improves speech-in-noise recognition. In addition, the time course could also support the protective function offered by the medial efferents. However, the current knowledge of efferent time constants is limited to a few probe frequencies (e.g., 1000 Hz) in limited subjects. The time course of medial efferent activation might be different for other probe frequencies or elicitors. In this study, the time course of the medial olivocochlear reflex was measured using stimulus frequency otoacoustic emissions recorded at spectral peaks near 1000 and 4000 Hz with broadband elicitors in 17 normal-hearing adults. Several preliminary but important findings emerged: (1) The onset response could be fitted with fast, medium, and/or slow time constants for limited subjects; (2) The magnitude (30–40%) of the efferent effect was similar to those reported in the literature; (3) The overall decay time appears to be longer for 4000 Hz relative to 1000 Hz; and (4) There was large individual variability in all response parameters across subjects. These findings will be discussed in detail. [Work supported by NIH/NIDCD R01DC018046.]
Normalization of speech kinematic data for characterizing primary muscle tension dysphonia
Authors: Shipurkar Riya , White Mackenzie , Katz William
Published: November 2023

Primary muscle tension dysphonia (pMTD) is a voice disorder of unknown etiology in which people have reduced volume and become easily fatigued. The tongue has biomechanical linkage to the laryngeal motor system that affects the voice, suggesting that tongue movement variability might be a marker for this disorder. Previous studies of healthy/disordered speech have reduced individual talker differences in physical vocal tract characteristics via normalization procedures. Here, we obtained tongue movement data for diadochokinetic sequences produced by healthy adult talkers and people with pMTD. We used an electromagnetic articulography system to test three healthy adult talkers and a participant with pMTD. We recorded vertical displacement of the tongue dorsum for sustained /a/ and 30 sec of rapidly repeated /pataka/. Displacement (mm) was scaled relative to each talker’s sustained vowel production, while movement time (msec) was normalized by dividing each /ka/ portion by the corresponding /pataka/ utterance length. The results suggest (1) normalization effectively reduced talker variability in tongue movement displacement and timing, and (2) the talker with pMTD showed markedly higher temporal variability, compared to the control talkers. We are currently testing this putative group difference using additional participants.
Source range and depth estimation of propeller cavitation bubble collapse transients in a multipath environment
Authors: Ferguson Brian G. , Ferguson Eric L.
Published: November 2023

An experiment is conducted in which a wide aperture array, which is proximate to the sea floor in water 20 m deep, records transits of two motorboats. Occasionally, acoustic transients, which are attributed to collapsing propeller cavitation bubbles, are observed to be superimposed on the continuous broadband radiated noise component of each of the array’s three widely spaced hydrophones. By measuring the time differences of arrival of the transient signals propagating via the direct path at adjacent pairs of hydrophones, passive ranging by wavefront curvature is used to estimate the range and bearing of the transient source. Next, the source depth is estimated by measuring the multipath delay of the surface reflected transient signal. Also, the spectrogram of a single hydrophone’s output is observed to display a Lloyd’s mirror interference pattern due to the direct propagation path of the broadband radiated noise combining with the indirect propagation path signal reflected from the sea floor. The reciprocal of the frequency difference between adjacent destructive interference fringe minima is equal to the multipath time delay. This multipath delay, which equates to the quefrency of the cepstrum’s first rahmonic, contains source range information. The results of the two passive ranging methods are presented.
Improving mode extraction with physics-informed neural network
Authors: Yoon Seunghyun , Park Yongsung , Seong Woojae
Published: November 2023

This study aims to enhance conventional mode extraction methods in ocean waveguides using a physics-informed neural network (PINN). Mode extraction involves estimating mode wavenumbers and corresponding mode depth functions. The approach considers a scenario with a single frequency source towed at a constant depth and measured from a vertical line array (VLA). Conventional mode extraction methods applied to experimental data face two problems. First, mode shape estimation is limited because the receivers only cover a partial waveguide. Second, the wavenumber spectrum is affected by issues such as Doppler shift and range errors. To address these challenges, we train the PINN with measured data, generating a densely sampled complex pressure field, including the unmeasured region above the VLA. We then apply the same mode extraction methods to both the raw data and the PINN-generated data for comparison. The proposed method is validated using data from the SWellEx-96, demonstrating improved mode extraction performance compared to using raw experimental data directly.
Deep learning approach to generate propeller cavitation noise
Authors: Kim Youngjoo , Choi Jongkwon , Hong Wooyoung , Lee Keunhwa
Published: November 2023

In underwater acoustic simulators, propeller cavitation noise has traditionally been modeled as a modulated broadband signal. This study aims to enhance the realism of these simulators by employing deep learning to generate propeller cavitation noise. The training data were collected from the modeled propeller under various pressure conditions in the Samsung Cavitation Tunnel. We have utilized a variant of Generative Adversarial Networks (GANs), wherein both the generator and discriminator are designed with a recursive structure. To assess the advantages of our data-based approach, we analyze the characteristics of the signals generated and compare them with the real signals or the modeled signal based on physics. The results demonstrate the effectiveness of our proposed model in generating realistic propeller cavitation signals. [Work supported by the Korea Research Institute for Defense Technology Planning and Advancement (20-106-B00-003).]
What does protection sound like? A modern approach to understanding New Zealand’s underwater soundscapes and acoustic anthropogenic pressures
Authors: Stanley Jenni A. , Crowe Leah M.
Published: November 2023

Global marine ecosystems have experienced degradation and loss of biodiversity as a result of human impacts and climate change. Monitoring of ecologically significant areas is vital in understanding these effects and their subsequent management. Soundscapes offer a unique opportunity for examining organisms and habitats in a way that eliminate many potential weaknesses of traditional monitoring techniques. This fundamental property of every environment is being increasingly influenced by the presence of human activities but is not yet recognized for the breadth of information it holds, and as a key indicator of change in an ecosystem. A nation-wide program, focusing on several high-priority protection sites, utilize passive acoustic monitoring (PAM) creating baseline datasets. With the emphasis on characterizing the ambient soundscapes and acoustic signatures of significant species, identifying key acoustic parameters that reflect ecosystem health and biodiversity, and in locations where human use will potentially contribute to negative acoustic exposures. Here, spatiotemporal trends in the underwater soundscapes at sites within Fiordland National Park are reported, illustrating diel, lunar, and seasonal patterns in sound pressure levels, identifying biotic, abiotic, and anthropogenetic sound sources where possible. PAM is an increasingly useful tool in understanding anthropogenic presence and ecosystem status, and offers an effective, minimally invasive, and less labor-intensive way of monitoring marine ecosystems.
Emergence of metrically structured rhythms and inter-partner coordination in joint drum improvization
Authors: Han Alexander T. , Fujioka Takako
Published: November 2023

Improvization is a common aspect of music across cultures and eras. Due to its spontaneous nature, it often proves difficult to examine empirically how collective improvization evolves, unless genre-specific constraints are available and followed by experts (e.g., jazz). Here, we investigate the rhythmic dimension of free improvization by non-experts. We focus on two widely used approaches in joint musical improvization: call-and-response (trading) and simultaneous playing (tandem). We hypothesized that non-experts could engage in meaningful joint music-making with a model partner, and that they produce rhythmic patterns with different emergent structures depending on the task. The first author served as a confederate playing with each participant for five blocks each of trading and tandem tasks. To preserve the open-ended nature of improvization, neither metronome nor background music were provided. Preliminary analysis of the rhythmic content indicates that within-player inter-onset-intervals (IOI) reflected a clear hierarchical metrical structure. Additional analysis suggests bi-directional influence between partners in terms of IOI distribution, note density, and timbre choice. During tandem improvization, each partner favored timbres the other did not, showing a complementary pattern. During trading, timbre choice appears more imitative. Subjects also reported an increase in their self-assessed competence and enjoyment of the task over successive blocks.
Absorptive noise barrier development
Authors: Law Harvey , Law Jenny , Kierzkowski Marek
Published: November 2023

This paper reveals the development of an absorptive, self-supporting noise barrier panel for external applications. Designed for use as a temporary external noise barrier for construction sites and roadside noise barriers. The absorptive noise barrier panel is a module base design that is easy to assemble, disassemble, and re-deploy. The barrier panel utilizes recycled plastic materials, such as milk bottles and other soft plastics, making it one of the most environmentally friendly products. The barrier is manufactured in one process via a unique rotation molding method. It is weather resistant, aesthetically appealing, and offers great design flexibility. Standard size panels are 100 mm thick, by 2000 m wide x 500 mm high. The acoustic design is modeled to achieve NRC 0.85 at 100 mm thick based on an advanced air-flow resistive layer technique combined with an air cavity. The actual sound absorption measurement results are well in line with the predicted modeling. Such a case study potentially uncovers a whole new range of innovative absorptive noise barriers. Further studies and investigations are also recommended.
Voice quality alteration and its potential implications for voice therapy
Authors: Schiller Isabel S. , Krüger Karolin , Bin Ismail Firdous , Schlittmeier Sabine J , Schmidt Gerhard
Published: November 2023

Modulating a speaker’s auditory feedback is a valuable technique for investigating vocal motor control. In auditory feedback alteration (AFA) experiments, participants receive real-time perturbed feedback of their voice through earphones while producing vocalizations into a microphone. Previous studies primarily focused on pitch and amplitude alterations, which typically result in compensatory vocal responses. The purpose of this study is to present a voice resynthesis system, called VQ-Synth, designed for real-time auditory feedback alteration of the speaker’s voice quality in terms of hoarseness. While an initial version of VQ-Synth was implemented using Matlab, the system has now been enhanced in a real-time framework written in ANSI-C to achieve effective voice quality resynthesis with minimal delay. Additionally, a graphical user interface (GUI) was implemented to guide participants through the experiment. This work presents the technical architecture of VQ-Synth and its intended application in AFA experiments involving both healthy and dysphonic speakers. Furthermore, we discuss the potential implications of the system in the context of auditory cognition and voice therapy. We hope that the novel capabilities of VQ-Synth open up exciting possibilities for investigating how alterations in voice quality affect vocal motor control and how this knowledge can be applied in therapeutic settings.
Duration of vocal effects due to water resistance therapy
Authors: Echternach Matthias , Köberlein Marie , Guzman Marco , Laukkanen Anne Maria , Richter Bernhard , Köberlein Marie
Published: November 2023

There are only few data about effects of semi-occluded vocal tract exercises on vocal fold oscillation patterns in vivo. Furthermore, it has not yet been clarified for how long these effects last. Material: 16 subjects (8 non-pathological and 8 with vocal fold mass lesion) were asked to sustain a phonation on the vowel /i/. During phonation, the subjects were simultaneously recorded with transnasal high speed videoendoscopy (HSV, 20.000 fps), electroglottography, and audio signals. After that, these subjects performed a Water Resistance Therapy (WRT) for 10 min (tube 30 cm, 9 mm diameter, 5 cm below surface). Repeated measurements of sustained phonation were performed 0, 10, and 30 min after exercising. The data showed strong inter-individual differences concerning the courses of the different measures after WRT. For non-pathological voices, directly after WRT there was a lowering of the Glottal-Area-Waveform derived Period-Perturbation -Quotient, a lowering of the closing quotient. For pathological voices, however, such a decrease was not observable. Five minutes after the exercise such effect was not observable any more. WRT showed strong inter-individual effects in the courses of the evaluated measures. General tendencies of some measures directly after the intervention showed a brief effect of only a few minutes.
Anterior-posterior characterization of intraglottal flow fields in excised canine larynges
Authors: Michaud-Dorko Jacob , Farbos de Luzan Charles , Gutmark Ephraim , Oren Liran
Published: November 2023

It has been espoused that intraglottal flow separation vortices (FSVs) play a critical role in the rapid closure of the vocal fold vibrations by acting as an additional pulling force that affects the maximum flow declination rate (MFDR). Clinically, MFDR is important because studies showed it highly correlates with loudness, intelligibility, and vocal efficiency. Previous studies that aimed to characterize the influence of FSVs were focused on their role in the mid-coronal plane. In the current study, particle imaging velocimetry was used to measure the intraglottal flow, specifically the FSVs, in the anterior–posterior aspects of the glottis during the closing phase of the vocal fold vibrations. The results show that the FSVs are extending along the length of the vocal fold in the anterior–posterior direction and that there is a direct relation between the size of FSVs and the magnitudes of the glottal divergence angles. The results also show that the centroid of FSVs occurs towards the anterior direction, where larger divergence angles are observed. These findings suggest that the FSVs in the anterior aspect have a more significant effect on the aerodynamic force acting on the glottal wall than the FSVs in the posterior aspect.
Comparing direct and indirect glottal flow waveform measurements in excised canine larynges and synthetic vocal fold models
Authors: Michaud-Dorko Jacob , Farbos de Luzan Charles , Gutmark Ephraim , Oren Liran
Published: November 2023

Despite being considered the gold standard technique for delineating the flow glottogram during phonation, the inverse filtering technique has never been validated against actual volume flow measurements. This signal-processingtechnique uses the speech signal with vocal tract estimates to calculate the glottal flow waveform. The lack of validation stems from the difficulty of obtaining in-vivo flow measurements at the glottal exit. The current study aims to assess the accuracy of the inverse filtering technique by comparing its flow glottograms with direct, simultaneous volume flow measurement. A vocal tract with varied constrictions that mimic its shape according to specific vowels was connected to either an excised canine larynx or a synthetic vocal fold model. Direct volume flow measurements at the glottal exit were done using tomographic particle image velocimetry. Indirect measurements were obtained by fitting the known Rothenberg mask to the vocal tract and estimating the glottal flow waveform using the Glottal Enterprise system. Preliminary results indicate that the accuracy of the inverse filtering technique relies on the degree of vocal tract constriction. The flow glottogram aligns well with front, lax, and unrounded lip vowels, but its accuracy diminishes with tense and round vowels, particularly noticeable with the excised canine larynx.
A practical method for assessing and managing the risk of noise induced hearing loss for divers in high-noise underwater environments
Authors: Lawrence Benjamin C. , Jelleyman Reuben J.
Published: November 2023

The purpose of this study was to develop a method to assessing and managing the risk of noise induced hearing loss (NIHL) to commercial divers operating within or nearby sites with high underwater sound levels. Our method involves using a transfer function to convert underwater sound levels to airborne sound levels at the diver’s ear inside a helmet, which can then be assessed against the 85 dB LAeq (8 hour) exposure limit for NIHL. We measured this transfer function for a standard commercial diving helmet (Kirby Morgan 37) during nearby impact piling using a Soundtrap hydrophone in the water and Brüel and Kjær sound level meter with a type-1 microphone at the ear position. We then used the results to calculate a time limit for a diver to be in the water before the in-ear sound levels exceed the NIHL exposure limit.
Investigations of the acoustic-field autoproducts in three dimensions
Authors: Arciniega Leslie V. , Dowling David R.
Published: November 2023

Acoustic remote sensing tasks, such as remote unknown source localization, are commonly completed via signal processing schemes that are implemented in the bandwidth of the acoustic recordings. Interestingly, many such schemes can also be implemented at frequencies outside of the bandwidth of the recorded field—despite their absence from the recordings—by using the frequency-difference and frequency-sum autoproducts [Worthmann and Dowling, J. Acoust. Soc. Am., 141 (2017) 4579–4590]. Recent acoustic-field autoproduct studies have involved beamforming and source localization in shallow- and deep-ocean environments, and have addressed the impacts of refraction, shadow zones, rough surface scattering, and noise. These previous efforts primarily explored the properties of the autoproducts when the sound field primarily varies in two spatial dimensions. This presentation provides the results of a study of the autoproducts formed from the simple but fully three-dimensional acoustic fields arising from an isolated source placed in a uniform-sound-speed environment bounded by reflecting surfaces that are not parallel. This study indicates the extent to which the autoproduct properties associated with two dimensional acoustic-field variations extend to three dimensional acoustic-field variations. The results from theory and simulations are presented, and from laboratory water-tank measurements if time allows.
The Effects of Different Types of Training on Cognitive Performance in Professional Esports Players
Authors: Thillier Clément , Besombes Nicolas , Agbangla Nounagnon Frutueux , Vitiello Damien
Published: November 2023

Over the past decade, the number of studies on cognitive performance in esports has increased in line with its popularity. Cognitive functions like task switching, information processing, attention, and memory have been identified as an integral part of cognitive performance. In parallel, different types of training, ranging from physical to a combination of cognitive and motor tasks, have emerged as promising strategies to improve cognitive function and thus performance of esports players. However, only acute high-intensity interval training was studied in esports players and exclusively in recreational players. Due to the lack of specialized training programs for esports coaches, the small number of professional esports players and the relative youth of professional esports practice, there is a large gap in the literature regarding cognitive performance training methods to improve the cognitive performance of professional esports players. Based on these results, the present invited commentary encourages further studies to be conducted among professional esports players. Indeed, research perspectives are necessary to develop training protocols and optimal training schedules to improve professional esports players’ performance. In addition, this commentary supports the collaboration between academic and professional esports organizations. Finally, we provide recommendations to allow a win-win condition for both researchers and professional esports players in the future.
In vitro
activity of cefiderocol, a siderophore cephalosporin, against carbapenem-resistant hypervirulent
Klebsiella pneumoniae
in China
Authors: Zhao Jiankang , Pu Danni , Li Ziyao , Liu Xinmeng , Zhang Yulin , Wu Yongli , Zhang Feilong , Li Chen , Zhuo Xianxia , Lu Binghuai , Cao Bin
Published: November 2023

Cefiderocol is a siderophore cephalosporin that binds ferric iron and utilizes iron transporters to cross the cell membrane. Hypervirulent
Klebsiella pneumoniae
(hvKp) is known to produce more siderophores; in this case, the uptake of cefiderocol may be decreased. Therefore, the objective of this study was to evaluate the
in vitro
activity of cefiderocol against hvKp isolates. A total of 320 carbapenem-resistant
K. pneumoniae
(CRKp) isolates were collected in China between 2014 and 2022, including 171 carbapenem-resistant hvKp (CR-hvKp) and 149 carbapenem-resistant classical
K. pneumoniae
(CR-cKp). Quantitative detection of siderophores showed that the average siderophore production of CR-hvKp (234.6 mg/L) was significantly higher than that of CR-cKp (68.9 mg/L,
P
< 0.001). The overall cefiderocol resistance rate of CR-hvKp and CR-cKp was 5.8% (10/171) and 2.7% (4/149), respectively. The non-susceptible rates of both cefiderocol and siderophore production of CR-hvKp isolates were higher than those of CR-cKp in either NDM-1- or KPC-2-producing groups. The MIC90 and MIC50 for CR-hvKp and CR-cKp were 8 mg/L and 2 mg/L and 4 mg/L and 1 mg/L, respectively. The cumulative cefiderocol MIC distribution for CR-hvKp was significantly lower than that of CR-cKp isolates (
P
= 0.003). KL64 and KL47 consisted of 53.9% (83/154) and 75.7% (53/70) of the ST11 CR-hvKp and CR-cKp, respectively, and the former had significantly higher siderophore production. In summary, cefiderocol might be less effective against CR-hvKp compared with CR-cKp isolates, highlighting the need for caution regarding the prevalence of cefiderocol-resistant
K. pneumoniae
strains, particularly in CR-hvKp isolates.
MmoD regulates soluble methane monooxygenase and methanobactin production in
Methylosinus trichosporium
OB3b
Authors: Peng Peng , Yang Junwon , DiSpirito Alan A. , Semrau Jeremy D.
Published: November 2023

Methane oxidation by aerobic methanotrophs is well known to be strongly regulated by the availability of copper, i.e., the “copper switch.” That is, there are two forms of methane monooxygenase: a cytoplasmic or soluble methane monooxygenase (sMMO) and a membrane-bound or particulate methane monooxygenase (pMMO). sMMO is only expressed and active in the absence of copper, while pMMO requires copper. Previous work has also shown that one gene in the operon of the soluble methane monooxygenase
—mmoD
—also plays a critical role in the “copper switch,” but its function is still vague. Herein, we show that MmoD is not needed for the expression of genes in the sMMO gene cluster but is critical for the formation of sMMO polypeptides and sMMO activity in
Methylosinus trichosporium
OB3b, indicating that MmoD plays a key post-transcriptional role in the maturation of sMMO. Furthermore, data also show that MmoD controls the expression of methanobactin, a copper-binding compound used by some methanotrophs, including
M. trichosporium
OB3b, for copper sequestration. Collectively, these results provide greater insights into the components of the “copper switch” and provide new strategies to manipulate methanotrophic activity.

IMPORTANCE

Aerobic methanotrophs play a critical role in the global carbon cycle, particularly in controlling net emissions of methane to the atmosphere. As methane is a much more potent greenhouse gas than carbon dioxide, there is increasing interest in utilizing these microbes to mitigate future climate change by increasing their ability to consume methane. Any such efforts, however, require a detailed understanding of how to manipulate methanotrophic activity. Herein, we show that methanotrophic activity is strongly controlled by MmoD, i.e., MmoD regulates methanotrophy through the post-transcriptional regulation of the soluble methane monooxygenase and controls the ability of methanotrophs to collect copper. Such data are likely to prove quite useful in future strategies to enhance the use of methanotrophs to not only reduce methane emissions but also remove methane from the atmosphere.
Reduced toxin binding associated with resistance to Vip3Aa in the corn earworm (
Helicoverpa zea
)
Authors: Kerns Dawson D. , Yang Fei , Kerns David L. , Stewart Scott D. , Jurat-Fuentes Juan Luis
Published: November 2023

Transgenic corn and cotton that express Cry and Vip insecticidal proteins from the bacterium,
Bacillus thuringiensis
(Bt), have been valuable tools for the management of lepidopteran pests. In 2019, a Vip3Aa-resistant strain of
Helicoverpa zea
(CEW-Vip-RR) was isolated from F
2
screens of field populations in Texas. Characterizing the resistance mechanism in this strain is important for predicting the sustained efficacy of current commercial Bt traits and guiding the development of future transgenic traits. Resistance to insecticidal proteins in Bt traits is commonly associated with reduced toxin binding, with the exception of Vip3Aa resistance being associated to altered proteolytic processing in the insect host gut. Therefore, Vip3Aa protoxin processing was tested by incubation with midgut fluids from CEW-Vip-RR relative to a susceptible strain (CEW-SS). Finding no significant processing differences, alterations in Vip3Aa binding were tested by comparing binding of radiolabeled and biotinylated Vip3Aa toxin to midgut brush border membrane vesicles (BBMV) from CEW-Vip-RR and CEW-SS larvae. Specific Vip3Aa binding to CEW-Vip-RR BBMV in these experiments was consistently reduced when compared with CEW-SS BBMV. These results support that an altered Vip3Aa-receptor is associated with resistance in CEW-Vip-RR. Understanding this resistance mechanism could have important implications for resistance management decisions, considering widespread Cry1 and Cry2 resistance in
H. zea
populations.

IMPORTANCE

Helicoverpa zea
is a major crop pest in the United States that is managed with transgenic corn and cotton that produce insecticidal proteins from the bacterium,
Bacillus thuringiensis
(Bt). However,
H. zea
has evolved widespread resistance to the Cry proteins produced in Bt corn and cotton, leaving Vip3Aa as the only plant-incorporated protectant in Bt crops that consistently provides excellent control of
H. zea
. The benefits provided by Bt crops will be substantially reduced if widespread Vip3Aa resistance develops in
H. zea
field populations. Therefore, it is important to identify resistance alleles and mechanisms that contribute to Vip3Aa resistance to ensure that informed resistance management strategies are implemented. This study is the first report of reduced binding of Vip3Aa to midgut receptors associated with resistance.
Elizabethkingia anophelis
outer membrane vesicles as a novel vaccine candidate against infection: insights into immune response and potential for passive immunity
Authors: Yang Ya-Sung , Chen Hung-Jui , Chen Xiao-Chun , Tang Hung-Jen , Chang Fang-Ju , Huang Yun-Ling , Pan Yu-Ling , Kesavan Dinesh Kumar , Chen Huan-Yuan , Shang Hung-Sheng , Kuo Shu-Chen , Chen Te-Li , Chiang Ming-Hsien
Published: November 2023

The emerging pathogen
Elizabethkingia anophelis
poses severe threats to public health and has caused several outbreaks. The efficacy of antimicrobials is limited due to the pathogen’s innate multi-drug resistance to most antibiotics. Hence, novel approaches to treat
E. anophelis
infections are urgently needed. This study evaluated the immunogenic and protective effects of the imipenem-induced outer membrane vesicles (iOMVs) of
E. anophelis
as a vaccine. Mice immunized with iOMVs were completely protected during lethal-dose challenges. Passive immunization with hyperimmune sera and splenocytes conferred protection against lethal pneumonia. iOMVs also induced Th1-, Th2-, and Th17-driven immune responses. Immunization with iOMVs increased IgG1 and IgG2c isotype levels, and the antisera from immunized mice promoted complement-dependent bactericidal and opsonophagocytic activities against
E. anophelis
C08. Our study suggests that
E. anophelis
iOMVs are a promising vaccine candidate for preventing and treating
E. anophelis
infections and provides insights into the use of OMVs in vaccine development against the clinically emergent
E. anophelis
.

IMPORTANCE

Elizabethkingia anophelis
, a Gram-negative pathogen, causes infections such as bacteraemia, pneumonia, and neonatal meningitis. The pathogen resists most antimicrobial classes, making novel approaches urgently needed. In natural settings, Gram-negative bacteria secrete outer membrane vesicles (OMVs) that carry important molecules in the bacterial life cycle. These OMVs are enriched with proteins involved in virulence, survival, and carbohydrate metabolism, making them a promising source for vaccine development against the pathogen. This study investigated the efficacy of imipenem-induced OMVs (iOMVs) as a vaccine candidate against
E. anophelis
infection in a mouse pneumonia model. Mice immunized with iOMVs were completely protected during lethal-dose challenges. Passive immunization with hyperimmune sera and splenocytes conferred protection against lethal pneumonia. Further investigation is needed to understand the mechanisms underlying the protective effects of iOMV-induced passive immunity, such as the action on specific antibody subclasses or T cell subsets.
In situ
cell division and mortality rates of SAR11, SAR86,
Bacteroidetes
, and
Aurantivirga
during phytoplankton blooms reveal differences in population controls
Authors: Brüwer Jan D. , Orellana Luis H. , Sidhu Chandni , Klip Helena C. L. , Meunier Cédric L. , Boersma Maarten , Wiltshire Karen H. , Amann Rudolf , Fuchs Bernhard M.
Published: November 2023

Net growth of microbial populations, that is, changes in abundances over time, can be studied using 16S rRNA fluorescence
in situ
hybridization (FISH). However, this approach does not differentiate between mortality and cell division rates. We used FISH-based image cytometry in combination with dilution culture experiments to study net growth, cell division, and mortality rates of four bacterial taxa over two distinct phytoplankton blooms: the oligotrophs SAR11 and SAR86, and the copiotrophic phylum
Bacteroidetes
, and its genus
Aurantivirga
. Cell volumes, ribosome content, and frequency of dividing cells (FDC) co-varied over time. Among the three, FDC was the most suitable predictor to calculate cell division rates for the selected taxa. The FDC-derived cell division rates for SAR86 of up to 0.8/day and
Aurantivirga
of up to 1.9/day differed, as expected for oligotrophs and copiotrophs. Surprisingly, SAR11 also reached high cell division rates of up to 1.9/day, even before the onset of phytoplankton blooms. For all four taxonomic groups, the abundance-derived net growth (−0.6 to 0.5/day) was about an order of magnitude lower than the cell division rates. Consequently, mortality rates were comparably high to cell division rates, indicating that about 90% of bacterial production is recycled without apparent time lag within 1 day. Our study shows that determining taxon-specific cell division rates complements omics-based tools and provides unprecedented clues on individual bacterial growth strategies including bottom–up and top–down controls.

IMPORTANCE

The growth of a microbial population is often calculated from their numerical abundance over time. However, this does not take cell division and mortality rates into account, which are important for deriving ecological processes like bottom–up and top–down control. In this study, we determined growth by numerical abundance and calibrated microscopy-based methods to determine the frequency of dividing cells and subsequently calculate taxon-specific cell division rates
in situ
. The cell division and mortality rates of two oligotrophic (SAR11 and SAR86) and two copiotrophic (
Bacteroidetes
and
Aurantivirga
) taxa during two spring phytoplankton blooms showed a tight coupling for all four taxa throughout the blooms without any temporal offset. Unexpectedly, SAR11 showed high cell division rates days before the bloom while cell abundances remained constant, which is indicative of strong top–down control. Microscopy remains the method of choice to understand ecological processes like top–down and bottom–up control on a cellular level.
Harnessing multiplex crRNA enables an amplification-free/CRISPR-Cas12a-based diagnostic methodology for
Nosema bombycis
Authors: Zhang Huarui , Zhao Huijuan , Cao Lu , Yu Bin , Wei Junhong , Pan Guoqing , Bao Jialing , Zhou Zeyang
Published: November 2023

Nosema bombycis
is transmitted horizontally and vertically from infected female moths to progeny eggs, bringing substantial economic losses to sericulture production. Timely and accurate detection of
N. bombycis
can effectively block the spread of silkworm pébrine disease, which is of great significance for its prevention and control. In this study, we established a multiplex-crRNA CRISPR/Cas12a nucleic acid amplification-free detection method for
N. bombycis
.. Specificity and sensitivity assessments confirmed that this method specifically detects
N. bombycis
without cross-reacting with other pathogens. It can detect
N. bombycis
at levels as low as 2 pg of genomic DNA. This method could also provide information on pathogen quantification, which will be important for in-field applications and promotions.

IMPORTANCE

The multiplex-crRNA CRISPR/Cas12a detection method saves hands-on time, reduces the risk of aerosol pollution, and can be directly applied to detecting silkworms infected with
Nosema bombycis
. This study provides a new approach for the inspection and quarantine of silkworm pébrine disease in sericulture and provides a new method for the detection of other pathogens.
Supplemental Material: Early Cambrian Cambroclavus is a scleritomous eumetazoan unrelated to bryozoan or dasyclad algae
Authors: Xiang Kai , Yin Zongjun , al. et
Published: November 2023

Supplemental data and Figures S1–S5.  