bluuebunny/crossref_metadata_2025 huggingface dataset:
Histological and functional assessment of a Takotsubo cardiomyopathy model established by immobilization stress
Authors: Pei Quanwei , Yang Jiemei , Li Bin , Lin Pengqi , Zou Lina , Zhang Junpei , Yin Hongpeng , Sun Jingmei , Wang Xin , Vera A Nevzorova , Dong Zengxiang , Yin Dechun
Published: February 2024

Introduction

Takotsubo cardiomyopathy (TTC), also known as stress‐induced cardiomyopathy, resembles acute heart failure syndrome but lacks disease‐specific diagnosis and treatment strategies. TTC accounts for approximately 5–6% of all suspected cases of acute coronary syndrome in women. At present, animal models of TTC are often created by large amounts of exogenous catecholamines such as isoproterenol. However, isoproterenol injection cannot fully simulate the onset of stress‐induced cardiomyopathy in humans since stress is not an instantaneous event.

Methods

Rats were immobilized for 6 h per day for 1–14 days. To examine whether the TTC model was successful, echocardiography was employed; Elisa detected serum sympathetic activation markers; and the Open‐Field test (OFT) was used to analyze behavioral changes in rats after stress. Western blot and histology were used to assess sympathetic remodeling, inflammation levels, and fibrosis; qRT‐PCR was used to explore the levels of fibrosis and myocardial hypertrophy. The electrical stability of ventricular was determined by electrophysiological testing.

Results

The rats showed severe stress behavior and local sympathetic remodeling of the heart after only 1 day of stress. After 3 days of stress, the induction of ventricular tachyarrhythmia increased prominently. The highest incidence of TTC in rats was at 5 days of immobilization stress. The pathological left ventricular remodeling caused by immobilization (IMO) stress includes inflammatory infiltration, fibrosis, and myocardial hypertrophy.

Conclusions

Our study confirms the hypothesis that IMO stress can mimic Takotsubo cardiomyopathy, and the various effects on the heart depending on the duration of IMO stress. We observed the highest incidence of TTC occurred after 5 days of stress. Furthermore, there is a gradual occurrence of electrical and structural remodeling as the stress duration prolongs.
Permanent pacemaker implantation with hybrid endocardial perventricular approach in infancy: May be an alternative route in the absence of epicardial lead
Authors: Ergul Yakup , Sahin Gulhan Tunca , Kafali Hasan Candas , Onan Ismihan Selen
Published: February 2024

Despite the advancements in technology, establishing the optimal implantation technique for pediatric patients with a pacemaker (PM) indication remains challenging. Although the implantation of an epicardial PM is recommended, especially in children weighing less than 10 kg, transventricular placement of endocardial leads can be performed safely, offering a practical substitute for an epicardial pacing system, particularly in situations where a transvenous approach is unfeasible due to patient size, anatomical constraints or epicardial PM leads were not available as in our case.
Utility of routine follow‐up defibrillation safety margin testing in young patients with epicardial implantable cardioverter‐defibrillators
Authors: Leng Tomas , Griffeth Elaine , Stephens Elizabeth H. , Dearani Joseph A. , Cannon Bryan C. , Ackerman Michael J. , Wackel Philip L.
Published: February 2024

Background

Routine defibrillation threshold testing (DFT) of transvenous implantable defibrillators (ICDs) has largely been in decline. In patients with non‐transvenous ICDs that utilize subcutaneous and pleural ICD leads, serial DFT testing can detect a significant number of failures. Data about the utility of follow‐up defibrillation safety margin testing (DSM) testing in pediatric patients and young adults with an epicardial ICD are lacking.

Methods

Patients aged < 25 years old who underwent epicardial ICD placement at Mayo Clinic from 2014 to 2023 with at least one follow‐up DSM test were included. The patients were divided into a “routine” (R) and “clinically indicated” (CI) group based on the index of clinical concern. Inadequate DSM was defined as unsuccessful defibrillation at an output of less than 10 J below the maximum output of the device. The purpose of this study was to assess the utility of follow‐up DSM testing.

Results

An epicardial ICD system was placed in 122 patients. A total of 26 patients met inclusion criteria and underwent a total of 47 DSM follow up tests. Inadequate DSM occurred in 1/33 (3%) in the R group and 2/14 (14%) DSM tests in the CI group. The median follow‐up period was 54 and 36 months for the R and CI group, respectively.

Conclusions

Our data suggest that epicardial ICDs are reliable and routine follow‐up DSM testing may not be necessary for all patients. DSM testing should be performed in individuals with epicardial ICD systems when there is clinical concern about lead or coil performance.
The Value of Cultural Similarity for Predicting Migration: Evidence from Food and Drink Interests in Digital Trace Data
Authors: Coimbra Vieira Carolina , Lohmann Sophie , Zagheni Emilio
Published: February 2024

One of the strongest empirical regularities in spatial demography is that flows of migrants are positively associated with population stocks at origin and destination and are inversely related to distance. This pattern was formalized into what are known as gravity models of migration. Traditionally, distance is measured geographically, but other measures of distance, such as cultural distance, are also relevant in explaining migration flows. However, measures of cultural distance are not widely adopted in the literature on modeling migration flows, partially because of the difficulties associated with operationalizing and producing these measures across space and time. In this paper, we use a scalable approach to obtain proxies for measuring cultural similarity between countries by using Facebook data and illustrate the impact of incorporating these measures, based on food and drink interests, into gravity models for predicting migration. Our results show that, despite their limitations, the new measures of cultural similarity derived from Facebook data improve the prediction power of traditional gravity models and have a predictive capacity comparable to that of classic variables used in the literature, such as shared language and history. The results open up new opportunities for understanding the determinants of migration and for predicting migration when considering broader and complementary perspectives on the meaning and measurement of distance.
Navigating through learning tensions at the front end: How firms can motivate paradoxical thinking when screening the creativity of ideas
Authors: Röth Tobias , Heidenreich Sven , Schweitzer Fiona , Spieth Patrick
Published: February 2024

Idea screening is crucial as it must select the most promising ideas that are best suited to increase front‐end success. Although paradox theory indicates that learning tensions characterize the evaluation and screening of idea creativity, we know little about how idea screeners navigate through the associated competing demands. In response, we investigate the effects of idea screeners' paradoxical thinking on the assessment of the creativity of ideas as well as its motivational antecedents of paradoxical thinking. By analyzing a survey (N = 326) and an experiment (N = 292), we show that paradoxical thinking increases front‐end success and both dimensions of idea creativity (encompassing meaningfulness and novelty). In turn, by creating a motivational context (comprising decision autonomy, encouragement to take risks, and tolerance for mistakes), firms can provide the antecedents to adopt paradoxical thinking. Our study contributes to and extends the literature on screening idea creativity and paradox theory.
Identifying Profiles of Support for Legal Abortion Services in Zambia: A Latent Class Analysis
Authors: Rosen Joseph G. , Mbizvo Michael T. , Chelwa Nachela , Phiri Lyson , Cresswell Jenny A. , Filippi Veronique , Kayeyi Nkomba
Published: February 2024

Relative to neighboring countries, Zambia has among the most progressive abortion policies, but numerous sociopolitical constraints inhibit knowledge of pregnancy termination rights and access to safe abortion services. Multistage cluster sampling was used to randomly select 1,486 women aged 15–44 years from households in three provinces. We used latent class analysis (LCA) to partition women into discrete groups based on patterns of endorsed support for legalized abortion on six socioeconomic and health conditions. Predictors of probabilistic membership in latent profiles of support for legal abortion services were identified through mixture modeling. A three‐class solution of support patterns for legal abortion services emerged from LCA: (1) legal abortion opponents (∼58 percent) opposed legal abortion across scenarios; (2) legal abortion advocates (∼23 percent) universally endorsed legal protections for abortion care; and (3) conditional supporters of legal abortion (∼19 percent) only supported legal abortion in circumstances where the pregnancy threatened the fetus or mother. Advocates and Conditional supporters reported higher exposure to family planning messages compared to opponents. Relative to opponents, advocates were more educated, and Conditional supporters were wealthier. Findings reveal that attitudes towards abortion in Zambia are not monolithic, but women with access to financial/social assets exhibited more receptive attitudes towards legal abortion.
Phosphatidylcholine‐deficient suppressor mutant of Sinorhizobium meliloti, altered in fatty acid synthesis, partially recovers nodulation ability in symbiosis with alfalfa (Medicago sativa)
Authors: García‐Ledesma Juan Daniel , Cárdenas‐Torres Luis , Martínez‐Aguilar Lourdes , Chávez‐Martínez Ana I. , Lozano Luis , López‐Lara Isabel M. , Geiger Otto
Published: February 2024

Rhizobial phosphatidylcholine (PC) is thought to be a critical phospholipid for the symbiotic relationship between rhizobia and legume host plants. A PC‐deficient mutant of Sinorhizobium meliloti overproduces succinoglycan, is unable to swim, and lacks the ability to form nodules on alfalfa (Medicago sativa) host roots. Suppressor mutants had been obtained which did not overproduce succinoglycan and regained the ability to swim. Previously, we showed that point mutations leading to altered ExoS proteins can reverse the succinoglycan and swimming phenotypes of a PC‐deficient mutant. Here, we report that other point mutations leading to altered ExoS, ChvI, FabA, or RpoH1 proteins also revert the succinoglycan and swimming phenotypes of PC‐deficient mutants. Notably, the suppressor mutants also restore the ability to form nodule organs on alfalfa roots. However, nodules generated by these suppressor mutants express only low levels of an early nodulin, do not induce leghemoglobin transcript accumulation, thus remain white, and are unable to fix nitrogen. Among these suppressor mutants, we detected a reduced function mutant of the 3‐hydoxydecanoyl‐acyl carrier protein dehydratase FabA that produces reduced amounts of unsaturated and increased amounts of shorter chain fatty acids. This alteration of fatty acid composition probably affects lipid packing thereby partially compensating for the previous loss of PC and contributing to the restoration of membrane homeostasis.
The Ca2+‐MdCRF4‐MdWRKY9 module negatively affects apple fruit watercore formation by suppressing the transcription of MdSOT2
Authors: Li Hongjian , Si Yajing , Wang Hong , Liu Zhi , Lu Qian , Liu Li , Li Tong , Wang Aide
Published: February 2024

Watercore is a common physiological disease of Rosaceae plants, such as apples (Malus domestica), usually occurring during fruit ripening. Apple fruit with watercore symptoms is prone to browning and rotting, thus losing commercial viability. Sorbitol and calcium ions are considered key factors affecting watercore occurrence in apples. However, the mechanism by which they affect the occurrence of watercore remains unclear. Here, we identified that the transcription factor MdWRKY9 directly binds to the promoter of MdSOT2, positively regulates the transcription of MdSOT2, increases sorbitol content in fruit, and promotes watercore occurrence. Additionally, MdCRF4 can directly bind to MdWRKY9 and MdSOT2 promoters, positively regulating their expression. Since calcium ions can induce the ubiquitination and degradation of the transcription factor MdCRF4, they can inhibit the transcription of MdWRKY9 and MdSOT2 by degrading MdCRF4, thereby reducing the sorbitol content in fruit and inhibiting the occurrence of fruit watercore disease. Our data sheds light on how calcium ions mitigate watercore in fruit, providing molecular‐level insights to enhance fruit quality artificially.
Deciphering PDH1's role in mung bean domestication: a genomic perspective on pod dehiscence
Authors: Li Shuai , Li Yaling , Zhu Hong , Chen Liyang , Zhang Huiying , Lian Lijie , Xu Miaomiao , Feng Xilong , Hou Rui , Yao Xiaolin , Lin Yifan , Wang Huaying , Wang Xutong
Published: February 2024

Mung bean (Vigna radiata) stands as a crucial legume crop in Asia, contributing to food security. However, our understanding of the underlying genetic foundation governing domesticated agronomic traits, especially those linked to pod architecture, remains largely unexplored. In this study, we delved into the genomic divergence between wild and domesticated mung bean varieties, leveraging germplasm obtained from diverse sources. Our findings unveiled pronounced variation in promoter regions (35%) between the two mung bean subpopulations, suggesting substantial changes in gene expression patterns during domestication. Leveraging transcriptome analysis using distinct reproductive stage pods and subpopulations, we identified candidate genes responsible for pod and seed architecture development, along with Genome‐Wide Association Studies (GWAS) and Quantitative Trait Locus (QTL) analysis. Notably, our research conclusively confirmed PDH1 as a parallel domesticated gene governing pod dehiscence in legumes. This study imparts valuable insights into the genetic underpinnings of domesticated agronomic traits in mung bean, and simultaneously highlighting the parallel domestication of pivotal traits within the realm of legume crops.
Successful treatment pure red cell aplasia after ABO major mismatched allogeneic hematopoietic stem cell transplantation with avatrombopag and low dose rituximab
Authors: Cao Junjie , Lu Shaoyan , Luo Danjie , Pei Renzhi , Lu Ying , Chen Dong , Du Xiaohong , Li Shuangyue
Published: February 2024

Background

Pure red cell aplasia (PRCA) following allogeneic hematopoietic stem cell transplantation (allo‐HSCT) with ABO major incompatibility is characterized by transfusion dependent anemia. No standard treatment existed for PRCA following allo‐HSCT yet.

Study Design and Methods

We conducted a retrospective study, and reported our experience with the use of avatrombopag and lower dose rituximab to treat five patients with PRCA subsequent to major ABO‐incompatible allo‐HSCT.

Results

Five cases of PRCA were identified from 72 patients who underwent allo‐HSCT with major or bidirectional ABO mismatch. Cumulative incidence at Day +60 was 6.9% (5/72) at our center. All donor and recipient blood groups were A+ and O+, respectively. In the first three cases we reported, patients received erythropoietin, plasma exchange, and donor lymphocyte infusion, but none of them had any effect. After 4 weeks of treatment with low dose rituximab (100 mg/week) combined with avatrombopag (40 mg/day), favorable outcomes were obtained. According to the aforementioned experience, Cases 4 and 5 were administered low‐dose rituximab and avatrombopag in 3 months after transplantation, and erythroid response was observed on 3 weeks after treatment. Our patients tolerated low‐dose rituximab and avatrombopag well and experienced rapid efficacy, with a median duration of 3 weeks. Furthermore, no severe infection or thrombocytosis necessitated a dose adjustment.

Conclusion

Low‐dose rituximab and avatrombopag may be an effective treatment for patients with PRCA after major ABO‐incompatible allo‐HSCT. The patients should be treated at least 90 days post transplantation if conventional erythropoietin therapy fails.
Keloids in male genitalia—Systematic review and illustrative case report
Authors: Isoldi Felipe Contoli , Garcia Ariane , Vieites Luiza , Ferreira Lydia Masako
Published: February 2024

Keloid is the maximum expression of pathological fibroproliferative skin wound healing, whose pathophysiology is not yet fully understood. Its occurrence in the perineum and genitalia is uncommon. A systematic review was carried out regarding the occurrence and treatment of keloids on the penis. An illustrative case was also reported. The review used the PRISMA checklist and was registered in PROSPERO. The entire literature period up to April 2023 was searched in the EMBASE/Elsevier, Cochrane, Scopus, Medline, BVS, SciELO, and Lilacs databases. The inclusion criteria embraced primary studies, clinical trials, prospective or retrospective cohorts, case series, case–control studies and case reports. Three hundred and sixty‐one studies were found and 12 of them were included, consisting of 9 case reports and 3 case series. The most common triggering factor for keloid formation was circumcision, in 11 of the cases, of which more than half occurred in prepubescent children. Several therapies, associated or isolated, were used to treat the cases. Only one of the reported patients had scar recurrence after surgical treatment. Studies with better scientific evidence are needed to understand the involvement of keloids in male genitalia. However, keloid formation in this topography is rare, making it difficult to carry out more elaborate studies.
Diophantine approximation, large intersections and geodesics in negative curvature
Authors: Ghosh Anish , Nandi Debanjan
Published: February 2024

In this paper, we prove quantitative results about geodesic approximations to submanifolds in negatively curved spaces. Among the main tools is a new and general Jarník–Besicovitch type theorem in Diophantine approximation. Our framework allows manifolds of variable negative curvature, a variety of geometric targets, and logarithm laws as well as spiraling phenomena in both measure and dimension aspect. Several of the results are new also for manifolds of constant negative sectional curvature. We further establish a large intersection property of Falconer in this context.
Comparing the properties and growth of graphene on electrolytic and rolled Cu foils by chemical vapor deposition
Authors: Lee Woo Jin , Kim Sang Ho , Eom Jun Sun , Caron Arnaud
Published: February 2024

In this work, we use electrolytic copper foils as substrates for the deposition of graphene by chemical vapor deposition. We investigate the effects of preannealing conditions, methane injection time, and temperature to synthesize graphene with a similar quality as when grown on cold-rolled copper. We find that the electrolytic copper foil’s annealing conditions and CH4 injection temperature determine the quality of graphene.
Damage-indicating and self-healing anticorrosion coatings based on fluorescence resonance energy transfer and photothermal shape memory mechanism
Authors: Ding Rui , Zhang Xue-qi , Lv Jing , Ji An-lan , Zhang Yu-chen , Fu Jie , Lv Xiao , Yao Lan , Yang Sheng-ying , Mao Guo-qing , Liang Xuan , Yang Heng , Liu Jie , Yu Hai-bin
Published: February 2024

Self-healing coatings, which possess the ability to repair damage and restore corrosion resistance without significant human intervention, have become a hot topic in corrosion protection research. In this paper, (±)-10-camphorsulfonic acid-doped polyaniline is synthesized and then combined with copolyurethane (copPU) to form the photothermal shape memory composite polymer (CSPA-copPU). An aggregation-induced emission agent, named N’,2-bis[(E)-5-chloro-2-hydroxybenzylidene] hydrazine-1-carbohydrazide, is synthesized and applied to create a synergistic fluorescence system with a prepared chelation-enhanced fluorescence (CHEF) agent, named Rhodamine Benzimidazole. Under the CHEF behavior in response to Fe3+ and the fluorescence resonance energy transfer effect, the system exhibits a strong and sensitive fluorescence response to corrosion-generated Fe3+. Using electrospinning technology, CSPA-copPU@Fl fibers are prepared with CSPA-copPU as the shell and a mixture of fluorescent agents as the core solution and applied to create the composite coatings. The coatings effectively indicate damage in the form of fluorescence, providing guidance for infrared laser repair. CSPA facilitates the passivation of exposed steel. Under irradiation by an infrared laser, the surface temperature reaches the glass transition temperature of copPU and the epoxy binder. Through softening expansion and diffusion entanglement of molecular chains, scratches in the coatings are closed and repaired, and the corrosion resistance is restored to a level of intact coatings.
Growth of p-doped 2D-MoS2 on Al2O3 from spatial atomic layer deposition
Authors: Maas André , Mistry Kissan , Sleziona Stephan , Alshehri Abdullah H. , Asgarimoghaddam Hatameh , Musselman Kevin P. , Schleberger Marika
Published: February 2024

In this letter, we report on the synthesis of monolayers of MoS2 via chemical vapor deposition directly on thin films of Al2O3 grown by spatial atomic layer deposition. The synthesized monolayers are characterized by atomic force microscopy as well as confocal Raman and photoluminescence spectroscopies. Our data reveal that the morphology and properties of the 2D material differ strongly depending on its position on the substrate. Close to the material source, we find individual flakes with an edge length of several hundred microns exhibiting a tensile strain of 0.3 %, n-doping on the order of ne = 0.2 × 1013 cm−2, and a dominant trion contribution to the photoluminescence signal. In contrast to this, we identify a mm-sized region downstream, that is made up from densely packed, small MoS2 crystallites with an edge length of several microns down to the nanometer regime and a coverage of more than 70 %. This nano-crystalline layer shows a significantly reduced strain of only <0.02 %, photoluminescence emission at an energy of 1.86 eV with a reduced trion contribution, and appears to be p-doped with a carrier density of nh = 0.1 × 1013 cm−2. The unusual p-type doping achieved here in a standard chemical vapor deposition process without substitutional doping, post-processing, or the use of additional chemicals may prove useful for applications.
Atomistic simulations for investigation of substrate and salt effects on lipid in-source fragmentation in secondary ion mass spectrometry: A follow-up study
Authors: Kim Hoshin , Gorman Brittney L. , Taylor Michael J. , Anderton Christopher R.
Published: February 2024

In-source fragmentation (ISF) poses a significant challenge in secondary ion mass spectrometry (SIMS). These fragment ions increase the spectral complexity and can lead to incorrect annotation of fragments as intact species. The presence of salt that is ubiquitous in biological samples can influence the fragmentation and ionization of analytes in a significant manner, but their influences on SIMS have not been well characterized. To elucidate the effect of substrates and salt on ISF in SIMS, we have employed experimental SIMS in combination with atomistic simulations of a sphingolipid on a gold surface with various NaCl concentrations as a model system. Our results revealed that a combination of bond dissociation energy and binding energy between N-palmitoyl-sphingomyelin and a gold surface is a good predictor of fragment ion intensities in the absence of salt. However, ion-fragment interactions play a significant role in determining fragment yields in the presence of salt. Additionally, the charge distribution on fragment species may be a major contributor to the varying effects of salt on fragmentation. This study demonstrates that atomistic modeling can help predict ionization potential when salts are present, providing insights for more accurate interpretations of complex biological spectra.
In situ plasma pin-up clean process for backside bevel polymer removal, defect reduction, and queue time relaxation
Authors: Ye Benjamin B. , Song Ganquan , Ye Jeff J.
Published: February 2024

Polymeric residues and films of various thicknesses on the wafer backside and the edge frontside bevel and backside are known to cause substantial yield losses. An additional ex situ bevel etch step can clear away these buildups from the edge bevel area but not from the wafer backside. In this paper, we demonstrate a novel and innovative in situ pin-up plasma clean step that can effectively remove polymers from both the wafer backside and the edge bevel areas, eliminating the need for the bevel etch step. A physical analysis of blanket test wafers and patterned product wafers that have underwent the pin-up clean step in inductively coupled plasma and capacitively coupled plasma etch systems reveals that the pin-up clean step can reduce defect counts on product wafers and improve manufacturing cycle time and throughput by relaxing the queue time constraint.
Novel principal component analysis tool based on python for analysis of complex spectra of time-of-flight secondary ion mass spectrometry
Authors: Zhou Yadong , Jiang Peishi , Chen Ping , Jia Endong , Welch Cole S. , Zhao Qian , Dhas Jeffrey A. , Graham Emily B. , Chen Xingyuan , Zhang Xin , Zhu Zihua
Published: February 2024

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a powerful surface analysis tool, which can simultaneously provide elemental, isotopic, and molecular information with part per million (ppm) sensitivity. However, each spectrum may be composed of hundreds of ion signals, which makes the spectra data complex. Principal component analysis (PCA) is a multivariate analysis technique that has been widely used to figure out the variances among samples in ToF-SIMS spectra data analysis and is showing great success in the explanation of complex ToF-SIMS spectra. So far, several software tools have been developed for PCA of ToF-SIMS spectra; however, none of them are freely available. Such a situation leads to some difficulties in extending applications of PCA to various research fields. More importantly, it has long been challenging for common researchers to understand PCA plots and extract chemical differences among samples. In this work, we developed a new and flexible software tool (named “advanced spectra pca toolbox”) based on python for PCA of complex ToF-SIMS spectra along with an easy-to-read manual. It can generate data analysis reports automatically to explain chemical differences among samples, allowing less experienced researchers to easily understand tricky PCA results. Moreover, it is expandable and compatible with artificial intelligence/machine learning functions. Pure goethite and different lignin adsorbed goethite samples were used as a model system to demonstrate our new software tool, proving that our software tool can be readily used in complex spectra data processing. Our new software tool is open-source, convenient, flexible, and expandable. We expect this open-source tool will benefit the ToF-SIMS community.
Corrosion behavior of the NiCrAlY and NiSiAlY alloys with salt mixtures of NaCl/Na2SO4
Authors: Zheng Haiyang , Cui Tiancheng , Zhu Bing , Yu Xiaopeng , Yu Miao
Published: February 2024

The corrosion behavior of the NiCrAlY and NiSiAlY alloys with the salt mixtures of various NaCl/Na2SO4 ratios was investigated at 750 °C. The tested alloys corroded by 100% Na2SO4, 100% NaCl and NaCl/Na2SO4 salt mixtures (75/25, 50/50, and 25/75 wt. %) exhibited distinctive resistance and behavior. The NiCrAlY alloys suffered more severe corrosion with the increasing proportion of NaCl in the salt mixtures. However, the NiSiAlY alloys caused more intense attack when exposed to the salt mixtures of NaCl/Na2SO4 (75/25, 50/50, and 25/75 wt.). The complex mechanisms and the impact of salt composition on corrosion are also discussed.
Overflow waters in the western Irminger Sea modify deep sound speed structure and convergence zone propagation
Authors: Bhatt EeShan C. , Baggeroer Arthur B. , Weller Robert A.
Published: February 2024

Deep sound speed structure in the western Irminger Sea is found to be highly dynamic in comparison to the adiabatic (uniform) sound speed gradient underpinning data assimilation and modeling efforts around the globe. A beamed source parabolic equation model is used to illustrate how the resulting non-uniform sound speed structure at 1 to 1.5 km in depth and sound speed inversion near the seafloor produce observable effects on acoustic signals between a shallow source and shallow vertical line array at convergence zone ranges. Beamforming analysis shows that a uniform sound speed gradient leads to “ideal” interference patterns that do not capture or represent modeled convergence zone properties, such as location, strength, and sharpness. Overall findings suggest that in situ information about sound speed below 1 km is necessary for low frequency, long-range propagation studies, particularly in areas of complex thermohaline circulation.
Phase-preserving narrow- and wide-angle parabolic equations for sound propagation in moving media
Authors: Ostashev Vladimir E. , Colas Jules , Dragna Didier , Wilson D. Keith
Published: February 2024

Parabolic equations are among the most popular numerical techniques in many fields of physics. This article considers extra-wide-angle parabolic equations, wide-angle parabolic equations, and narrow-angle parabolic equations (EWAPEs, WAPEs, and NAPEs, respectively) for sound propagation in moving inhomogeneous media with arbitrarily large variations in the sound speed and Mach number of the (subsonic) wind speed. Within their ranges of applicability, these parabolic equations exactly describe the phase of the sound waves and are, thus, termed the phase-preserving EWAPE, WAPE, and NAPE. Although variations in the sound speed and Mach number are often relatively small, omitting the second-order terms pertinent to these quantities can result in large cumulative phase errors for long propagation ranges. Therefore, the phase-preserving EWAPE, WAPE, and NAPE can be preferable in applications. Numerical implementation of the latter two equations can be performed with minimal modifications to existing codes and is computationally efficient. Numerical results demonstrate that the phase-preserving WAPE and NAPE provide more accurate results than the WAPE and NAPE based on the effective sound speed approximation.
Development of amplitude modulation, voice onset time, and consonant identification in noise and reverberation
Authors: Peng Z. Ellen , Easwar Vijayalakshmi
Published: February 2024

Children's speech understanding is vulnerable to indoor noise and reverberation: e.g., from classrooms. It is unknown how they develop the ability to use temporal acoustic cues, specifically amplitude modulation (AM) and voice onset time (VOT), which are important for perceiving distorted speech. Through three experiments, we investigated the typical development of AM depth detection in vowels (experiment I), categorical perception of VOT (experiment II), and consonant identification (experiment III) in quiet and in speech-shaped noise (SSN) and mild reverberation in 6- to 14-year-old children. Our findings suggested that AM depth detection using a naturally produced vowel at the rate of the fundamental frequency was particularly difficult for children and with acoustic distortions. While the VOT cue salience was monotonically attenuated with increasing signal-to-noise ratio of SSN, its utility for consonant discrimination was completely removed even under mild reverberation. The reverberant energy decay in distorting critical temporal cues provided further evidence that may explain the error patterns observed in consonant identification. By 11–14 years of age, children approached adult-like performance in consonant discrimination and identification under adverse acoustics, emphasizing the need for good acoustics for younger children as they develop auditory skills to process distorted speech in everyday listening environments.
Assessing accuracy of resonances obtained with reassigned spectrograms from the “ground truth” of physical vocal tract models
Authors: Shadle Christine H. , Fulop Sean A. , Chen Wei-Rong , Whalen D. H.
Published: February 2024

The reassigned spectrogram (RS) has emerged as the most accurate way to infer vocal tract resonances from the acoustic signal [Shadle, Nam, and Whalen (2016). “Comparing measurement errors for formants in synthetic and natural vowels,” J. Acoust. Soc. Am. 139(2), 713–727]. To date, validating its accuracy has depended on formant synthesis for ground truth values of these resonances. Synthesis is easily controlled, but it has many intrinsic assumptions that do not necessarily accurately realize the acoustics in the way that physical resonances would. Here, we show that physical models of the vocal tract with derivable resonance values allow a separate approach to the ground truth, with a different range of limitations. Our three-dimensional printed vocal tract models were excited by white noise, allowing an accurate determination of the resonance frequencies. Then, sources with a range of fundamental frequencies were implemented, allowing a direct assessment of whether RS avoided the systematic bias towards the nearest strong harmonic to which other analysis techniques are prone. RS was indeed accurate at fundamental frequencies up to 300 Hz; above that, accuracy was somewhat reduced. Future directions include testing mechanical models with the dimensions of children's vocal tracts and making RS more broadly useful by automating the detection of resonances.
Estimating distances to baleen whales using multipath arrivals recorded by individual seafloor seismometers at full ocean depth
Authors: Hilmo Rose , Wilcock William S. D.
Published: February 2024

Ocean bottom seismometer networks can record opportunistic data sets of 20-Hz fin whale calls. Because networks are often too sparse for multi-station tracking, single-station methods are needed to estimate call density. We investigated a method to range to singing fin whales at full ocean depths using the spacing of water column multiples. Calls were detected by cross-correlating a spectrogram with a template call. To enhance multipath signals, we considered 20-min windows and either summed the spectrograms of all calls aligned on the strongest detection before measuring the multipath spacing or measured the spacing directly from the autocorrelation of the cross correlation time series. We evaluated the methods at five sites with contrasting seafloor and subsurface properties, bathymetric relief, and water depths of 4000–6000 m, using fin whale songs at four sites and a sei whale song at the fifth. The autocorrelation method works best, and ranges can be obtained to >15 km. Ranging at sedimented sites requires careful accounting for subsurface reflections. Ranges have considerable uncertainty in regions of bathymetric relief. The method requires that the time between calls is different from that of the multipaths and does not work reliably when more than one whale is singing nearby.
Depth estimation for broadband sources with a vertical line array in deep water
Authors: Qi Yubo , Zhou Shihong , Liu Changpeng , Dun Jincong , Liu Shuanghu
Published: February 2024

In deep water, deploying a short vertical line array (VLA) is an effective way for source localization. In the past decade, most studies focused on localizing sources at the short to moderate ranges in the reliable acoustic path or the direct arrival zone (DAZ), with a VLA deployed near the ocean bottom. Little work has been done for the end part of the DAZ and the zones outside the DAZ. In addition, a VLA deployed at other depths rather than near the bottom is rarely studied. This paper proposes a near-surface source depth estimation method by matching the measured time delay with a library of modeled values under different source depths calculated by a simple formula. This method is suitable for zones, which contains two paths (one is reflected from the sea surface) with very close arrival angles, of a VLA deployed not only near the bottom, but also at other depths of the water column. Source depth estimation strategy for the end part of each zone, which faces the problem of poor depth resolution, is also analyzed. Simulation and experimental data of the airgun and explosive sources in the South China Sea are used to demonstrate the method.
An experimental sound exposure study at sea: No spatial deterrence of free-ranging pelagic fish
Authors: Hubert Jeroen , Demuynck Jozefien M. , Remmelzwaal M. Rafa , Muñiz Carlota , Debusschere Elisabeth , Berges Benoit , Slabbekoorn Hans
Published: February 2024

Acoustic deterrent devices are used to guide aquatic animals from danger or toward migration paths. At sea, moderate sounds can potentially be used to deter fish to prevent injury or death due to acoustic overexposure. In sound exposure studies, acoustic features can be compared to improve deterrence efficacy. In this study, we played 200–1600 Hz pulse trains from a drifting vessel and investigated changes in pelagic fish abundance and behavior by utilizing echosounders and hydrophones mounted to a transect of bottom-moored frames. We monitored fish presence and tracked individual fish. This revealed no changes in fish abundance or behavior, including swimming speed and direction of individuals, in response to the sound exposure. We did find significant changes in swimming depth of individually tracked fish, but this could not be linked to the sound exposures. Overall, the results clearly show that pelagic fish did not flee from the current sound exposures, and we found no clear changes in behavior due to the sound exposure. We cannot rule out that different sounds at higher levels elicit a deterrence response; however, it may be that pelagic fish are just more likely to respond to sound with (short-lasting) changes in school formation.
Connecting poro- and visco-elastic acoustic models of marine sediments: Salinity, force chains, creep, and permeability
Authors: Chotiros Nicholas P.
Published: February 2024

A poro-elastic model for both sandy and muddy marine sediments is used to derive a visco-elastic approximation, and compared to the existing measurements of wave speeds, attenuations, and reflection. The poro-elastic model is the modified, corrected, Revil, extended Biot (mCREB) model. Its derivation, which includes a force chain approximation and a creep mechanism, is reviewed and equations for implementation are provided. It fits the existing measurements over a broad range of frequencies from a few Hertz to almost a megaHertz. Salinity is essential to the poro-elastic behavior of mud. A visco-elastic approximation is derived, based on the zero permeability condition. It is a simpler model with fewer input parameters, and practically identical to the popular viscous grain shearing (VGS) model, although their derivations are very different. Comparisons between the measurements, the poro-elastic model, and its visco-elastic approximation are made in order to identify the circumstances in which the latter may be used. Generally, the visco-elastic approximation may be used for frequencies below 1 kHz in mud and sand. At higher frequencies, poro-elastic effects dominate rendering the visco-elastic approximation inaccurate.
The Rossiter equation: Improving the fractional vortex speed and defining an effective length to depth ratio for cavity flows
Authors: Gabel Matthew , Sarigul-Klijn Nesrin
Published: February 2024

This paper first reviews well known analytical techniques for predicting the Rossiter modes of a cavity in compressible flow. We combine existing methods to improve the performance in compressible flow. Second, we introduce a method based on an effective length to depth ratio of the cavity from experimental results for predicting frequencies across Mach numbers. Finally, the fractional vortex speed used in the Rossiter equation and its derivatives is calculated from high subsonic (M 0.55) to supersonic (M 2.3) for use in future cavity mode prediction.
Data-driven decomposition of crowd noise from indoor sporting events
Authors: Cutler Mitchell C. , Cook Mylan R. , Transtrum Mark K. , Gee Kent L.
Published: February 2024

Separating crowd responses from raw acoustic signals at sporting events is challenging because recordings contain complex combinations of acoustic sources, including crowd noise, music, individual voices, and public address (PA) systems. This paper presents a data-driven decomposition of recordings of 30 collegiate sporting events. The decomposition uses machine-learning methods to find three principal spectral shapes that separate various acoustic sources. First, the distributions of recorded one-half-second equivalent continuous sound levels from men's and women's basketball and volleyball games are analyzed with regard to crowd size and venue. Using 24 one-third-octave bands between 50 Hz and 10 kHz, spectrograms from each type of game are then analyzed. Based on principal component analysis, 87.5% of the spectral variation in the signals can be represented with three principal components, regardless of sport, venue, or crowd composition. Using the resulting three-dimensional component coefficient representation, a Gaussian mixture model clustering analysis finds nine different clusters. These clusters separate audibly distinct signals and represent various combinations of acoustic sources, including crowd noise, music, individual voices, and the PA system.
Evolution of acoustic nonlinearity in outdoor blast propagation from firearms: On the persistence of nonlinear behavior
Authors: Billot Guido , Marinus Benoît G. , Harri Kristof , Moiny Francis
Published: February 2024

Acoustic events exceeding a certain threshold of intensity cannot benefit from a linearization of the governing wave equation, posing an additional burden on the numerical modelling. Weak shock theory associates nonlinearity with the generation of high frequency harmonics that compensate for atmospheric attenuation. Overlooking the persistence of this phenomenon at large distances can lead to mispredictions in gun detection procedures, noise abatement protocols, and auditory risk assessment. The state-of-the-art mostly addresses aircraft jet noise, a stationary and largely random type of signal. The extension of such conclusions to muzzle blasts requires caution in considering their peculiar impulsive and broadband nature. A methodology based on the time and frequency analysis of an experimental dataset of eight calibres intends to find quantitative metrics linked to acoustic nonlinearity in outdoor muzzle blast propagation. Propagating three waveforms (SCAR-L 7.62 mm, Browning 9 mm, and Howitzer 105 mm) up to 300 [m] with the in-house numerical solver based on the nonlinear progressive wave equation, demonstrates that the propagation does not downgrade to truly linear.
Room impulse response reconstruction with physics-informed deep learning
Authors: Karakonstantis Xenofon , Caviedes-Nozal Diego , Richard Antoine , Fernandez-Grande Efren
Published: February 2024

A method is presented for estimating and reconstructing the sound field within a room using physics-informed neural networks. By incorporating a limited set of experimental room impulse responses as training data, this approach combines neural network processing capabilities with the underlying physics of sound propagation, as articulated by the wave equation. The network's ability to estimate particle velocity and intensity, in addition to sound pressure, demonstrates its capacity to represent the flow of acoustic energy and completely characterise the sound field with only a few measurements. Additionally, an investigation into the potential of this network as a tool for improving acoustic simulations is conducted. This is due to its proficiency in offering grid-free sound field mappings with minimal inference time. Furthermore, a study is carried out which encompasses comparative analyses against current approaches for sound field reconstruction. Specifically, the proposed approach is evaluated against both data-driven techniques and elementary wave-based regression methods. The results demonstrate that the physics-informed neural network stands out when reconstructing the early part of the room impulse response, while simultaneously allowing for complete sound field characterisation in the time domain.
Acoustic pressure modulation driven by spatially non-uniform flow
Authors: Denner Fabian
Published: February 2024

The recent identification of a modulation of acoustic waves that is driven by spatial velocity gradients, using acoustic black and white hole analogues [see Schenke, Sewerin, van Wachem, and Denner, J. Acoust. Soc. Am. 154, 781–791 (2023)], has shed new light on the complex interplay of acoustic waves and non-uniform flows. According to the virtual acoustic black hole hypothesis, these findings should be applicable to acoustic waves propagating in non-uniform flows of arbitrary velocity. In this study, the propagation of acoustic waves in non-uniform flows is investigated by incorporating a leading-order model of acoustic pressure modulation into a Lagrangian wave tracking algorithm. Using this numerical method, the acoustic pressure modulation is recovered accurately in non-uniform subsonic flows. This suggests that spatial velocity gradients drive acoustic pressure modulations in any non-uniform flow, which can, as shown here, be readily quantified.
Relevance of phase information for object classification in automotive ultrasonic sensing using convolutional neural networks
Authors: Eisele Jona , Gerlach André , Maeder Marcus , Marburg Steffen
Published: February 2024

Automotive ultrasonic sensors come into play for close-range surround sensing in parking and maneuvering situations. In addition to ultrasonic ranging, classifying obstacles based on ultrasonic echoes to improve environmental perception for advanced driver-assistance systems is an ongoing research topic. Related studies consider only magnitude-based features for classification. However, the phase of an echo signal contains relevant information for target discrimination. This study discusses and evaluates the relevance of the target phase in echo signals for object classification in automotive ultrasonic sensing based on lab and field measurements. Several phase-aware features in the time domain and time-frequency features based on the continuous wavelet transform are proposed and processed using a convolutional neural network. Indeed, phase features are found to contain relevant information, producing only 4% less classification accuracy than magnitude features when the phase is appropriately processed. The investigation reveals high redundancy when magnitude and phase features are jointly fed into the neural network, especially when dealing with time-frequency features. However, incorporating the target phase information facilitates the identification quality in high clutter environments, increasing the model's robustness against signals with low signal-to-noise ratios. Ultimately, the presented work takes one further step toward enhanced object discrimination in advanced driver-assistance systems.
Tonguedness in speech: Lateral bias in lingual bracing
Authors: Liu Yadong , Islam Jahurul , Radford Kate , Tkachman Oksana , Gick Bryan
Published: February 2024

This study examines the lateral biases in tongue movements during speech production. It builds on previous research on asymmetry in various aspects of human biology and behavior, focusing on the tongue's asymmetric behavior during speech. The findings reveal that speakers have a pronounced preference toward one side of the tongue during lateral releases with a majority displaying the left-side bias. This lateral bias in tongue speech movements is referred to as tonguedness. This research contributes to our understanding of the articulatory mechanisms involved in tongue movements and underscores the importance of considering lateral biases in speech production research.