Sound propagation in realistic interactive 3D scenes with parameterized sources using deep neural operators.

We address the challenge of acoustic simulations in three-dimensional (3D) virtual rooms with parametric source positions, which have applications in virtual/augmented reality, game audio, and spatial computing. The wave equation can fully describe wave phenomena such as diffraction and interference. However, conventional numerical discretization methods are computationally expensive when simulating hundreds of source and receiver positions, making simulations with parametric source positions impractical. To overcome this limitation, we propose using deep operator networks to approximate linear wave-equation operators. This enables the rapid prediction of sound propagation in realistic 3D acoustic scenes with parametric source positions, achieving millisecond-scale computations. By learning a compact surrogate model, we avoid the offline calculation and storage of impulse responses for all relevant source/listener pairs. Our experiments, including various complex scene geometries, show good agreement with reference solutions, with root mean squared errors ranging from 0.02 to 0.10 Pa. Notably, our method signifies a paradigm shift as-to our knowledge-no prior machine learning approach has achieved precise predictions of complete wave fields within realistic domains.

Just noticeable difference for simulation accuracy between full and reduced order models (L).

Model order reduction techniques significantly reduce the computational time when performing accurate room acoustic simulations with numerical methods that inherently include all the wave phenomena. There is a clear trade-off between physical accuracy and acceleration, but how humans perceive these errors is unknown. This study aims to investigate physical error limit that does not induce perceptual differences. Various two-dimensional rooms and reverberation times are tested with a three-alternative forced-choice listening test. Results reveal that for the presented cases, the threshold stands between a relative root mean square error of 1% and 0.1%, where the reduced order model stimulus results in a statistically significant difference.

Reduced order modelling using parameterized non-uniform boundary conditions in room acoustic simulations.

Quick simulations for iterative evaluations of multi-design variables and boundary conditions are essential to find the optimal acoustic conditions in building design. We propose to use the reduced basis method (RBM) for realistic room acoustic scenarios where the surfaces have inhomogeneous acoustic properties, which enables quick evaluations of changing absorption materials for different surfaces in room acoustic simulations. The RBM has shown its benefit to speed up room acoustic simulations by 3 orders of magnitude for uniform boundary conditions. This study investigates the RBM with two main focuses: (1) various source positions in diverse geometries, e.g., square, rectangular, L-shaped, and disproportionate room, (2) two-dimensional and three-dimensional (3D) inhomogeneous surface absorption by parameterizing numerous acoustic parameters of surfaces, e.g., the thickness of a porous material, cavity depth, switching between a frequency independent (e.g., hard surface) and frequency dependent boundary condition. Results of numerical experiments show speedups of more than 2 orders of magnitude compared to a high fidelity numerical solver in a 3D case where reverberation time varies within one just noticeable difference in all the frequency octave bands.

Esthetic reconstruction of a localized severely resorbed anterior maxilla associated with peri-implantitis: A clinical report.

This clinical report described the esthetic reconstruction of a localized severely resorbed right anterior maxilla associated with peri-implantitis. For vertical bone augmentation, guided bone regeneration surgery was performed by raising a flap with the remote incision technique, followed by soft tissue grafting and vestibuloplasty. The biologically oriented preparation technique was used to improve the health and stability of the peri-implant tissues. The surgical treatment and a novel method of prosthetic rehabilitation provided excellent esthetic and functional outcomes.

Hidden energies around surfaces, edges, and corners in rooms.

The Reflections series takes a look back on historical articles from The Journal of the Acoustical Society of America that have had a significant impact on the science and practice of acoustics.

Reduced basis methods for numerical room acoustic simulations with parametrized boundaries.

The use of model-based numerical simulations of wave propagation in rooms for engineering applications requires that acoustic conditions for multiple parameters are evaluated iteratively, which is computationally expensive. We present a reduced basis method (RBM) to achieve a computational cost reduction relative to a traditional full-order model (FOM) for wave-based room acoustic simulations with parametrized boundaries. The FOM solver is based on the spectral-element method; however, other numerical methods could be applied. The RBM reduces the computational burden by solving the problem in a low-dimensional subspace for parametrized frequency-independent and frequency-dependent boundary conditions. The problem is formulated in the Laplace domain, which ensures the stability of the reduced-order model (ROM). We study the potential of the proposed RBM in terms of computational efficiency, accuracy, and storage requirements, and we show that the RBM leads to 100-fold speedups for a two-dimensional case and 1000-fold speedups for a three-dimensional case with an upper frequency of 2 and 1 kHz, respectively. While the FOM simulations needed to construct the ROM are expensive, we demonstrate that the ROM has the potential of being 3 orders of magnitude faster than the FOM when four different boundary conditions are simulated per room surface.

Bee Venom Activates the Nrf2/HO-1 and TrkB/CREB/BDNF Pathways in Neuronal Cell Responses against Oxidative Stress Induced by Aß1-42.

Honeybee venom has recently been considered an anti-neurodegenerative agent, primarily due to its anti-inflammatory effects. The natural accumulation of amyloid-beta (Aß) in the brain is reported to be the natural cause of aging neural ability downfall, and oxidative stress is the main route by which Aß ignites its neural toxicity. Anti-neural oxidative stress is considered an effective approach for neurodegenerative therapy. To date, it is unclear how bee venom ameliorates neuronal cells in oxidative stress induced by Aß. Here, we evaluated the neuroprotective effect of bee venom on Aß-induced neural oxidative stress in both HT22 cells and an animal model. Our results indicate that bee venom protected HT22 cells against apoptosis induced by Aß1-42. This protective effect was explained by the increased nuclear translocation of nuclear factor erythroid 2-like 2 (Nrf2), consequently upregulating the production of heme oxygenase-1 (HO-1), a critical cellular instinct antioxidant enzyme that neutralizes excessive oxidative stress. Furthermore, bee venom treatment activated the tropomyosin-related kinase receptor B (TrkB)/cAMP response element-binding (CREB)/brain-derived neurotrophic factor (BDNF), which is closely related to the promotion of cellular antioxidant defense and neuronal functions. A mouse model with cognitive deficits induced by Aß1-42 intracerebroventricular (ICV) injections was also used. Bee venom enhanced animal cognitive ability and enhanced neural cell genesis in the hippocampal dentate gyrus region in a dose-dependent manner. Further analysis of animal brain tissue and serum confirmed that bee venom reduced oxidative stress, cholinergic system activity, and intercellular neurotrophic factor regulation, which were all adversely affected by Aß1-42. Our study demonstrates that bee venom exerts antioxidant and neuroprotective actions against neural oxidative stress caused by Aß1-42, thereby promoting its use as a therapeutic agent for neurodegenerative disorders.

Force-Free Control for Direct Teaching of a Surgical Assistant Robot End Effector with Wire-Driven Bidirectional Telescopic Mechanism.

This paper shows the design and modeling of an end effector with a bidirectional telescopic mechanism to allow a surgical assistant robot to hold and handle surgical instruments. It also presents a force-free control algorithm for the direct teaching of end effectors. The bidirectional telescopic mechanism can actively transmit force both upwards and downwards by staggering the wires on both sides. In order to estimate and control torque via motor current without a force/torque sensor, the gravity model and friction model of the device are derived through repeated experiments. The LuGre model is applied to the friction model, and the static and dynamic parameters are obtained using a curve fitting function and a genetic algorithm. Direct teaching control is designed using a force-free control algorithm that compensates for the estimated torque from the motor current for gravity and friction, and then converts it into a position control input. Direct teaching operation sensitivity is verified through hand-guiding experiments.

Four-Year Interim Results of the Safety of Augmentation Mammaplasty Using the Motiva Ergonomix™ Round SilkSurface: A Multicenter, Retrospective Study.

BACKGROUND: The Motiva Ergonomix™ Round SilkSurface (Establishment Labs Holdings Inc., Alajuela, Costa Rica) is the fifth generation of a silicone gel-filled breast implant that is commercially available in Korea. OBJECTIVES: In this study, we describe 4-year interim results of the safety of augmentation mammaplasty using the Motiva Ergonomix™ Round SilkSurface in Korean women. METHODS: In the current multicenter, retrospective study, we performed a retrospective review of medical records of a total of 1314 patients who received augmentation mammaplasty using the Motiva Ergonomix™ Round SilkSurface at our hospitals between September 1, 2016, and August 31, 2020. For safety assessment, we analyzed incidences of postoperative complications and Kaplan-Meier complication-free survival of the patients. RESULTS: We included a total of 873 patients (1746 breasts, mean age = 32.18 ± 6.88 years) in the current study. There were a total of 111 cases (12.70%) of postoperative complications; these include 24 cases (2.70%) of early seroma, 18 cases (2.10%) of hematoma, 18 cases (2.10%) of capsular contracture, 17 cases (1.95%) of dissatisfaction with shape, 16 cases (1.83%) of dissatisfaction with size, 9 cases (1.03%) of asymmetry, 6 cases (0.70%) of infection and 3 cases (0.34%) of rippling. Moreover, time-to-events were estimated at 918.34 ± 36.22 days (95% CI 845.44-988.52). CONCLUSIONS: Here, we describe 4-year interim results of the safety of augmentation mammaplasty using the Motiva Ergonomix™ Round SilkSurface in Korean women in a non-manufacturer-sponsored study. But further large-scale, prospective, multicenter studies with a long period of follow-up are warranted to establish our results. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A Preliminary Retrospective Study to Assess the Short-Term Safety of Traditional Smooth or Microtextured Silicone Gel-Filled Breast Implants in Korea.

Background and objectives: We conducted this preliminary retrospective study to assess the short-term safety of silicone gel-filled breast implants (SGBIs) that are commercially available in Korean women. Materials and methods :The current retrospective, observational study was conducted in a total of 2612 patients (n = 2612) who underwent augmentation mammaplasty using breast implants at our hospitals between 1 January 2017 and 31 August 2021. Results: Overall, there were a total of 248 cases (9.49%) of postoperative complications; these include 112 cases of early seroma, 52 cases of shape deformation, 32 cases of CC, 12 cases of early hematoma, 12 cases of rupture, 12 cases of infection, 12 cases of stretch deformities with skin excess and 4 cases of rippling. Overall complication-free survival of the breast implant was estimated at 1564.32 ± 75.52 days (95% CI 1416.39-1712.32). Then, the Motiva Ergonomix™ SilkSurface showed the longest survival (1528.00 ± 157.92 days [95% CI 1218.48-1837.56]), followed by the BellaGel® SmoothFine (1458.4 ± 65.76 days [95% CI 1329.56-1587.28]), the Sebbin® Sublimity (1322.00 ± 51.20 days [95% CI 1221.64-1422.32]), the BellaGel® Smooth (1138.72 ± 161.28 days [95% CI 822.6-1454.84), the Mentor® MemoryGel™ Xtra (698.4 ± 52.64 days [95% CI 595.28-801.52]) and the Natrelle® INSPIRA™ (380.00 ± 170.88 days [95% CI 45.04-714.96]) in the decreasing order. On subgroup analysis, both the Motiva ErgonomixTM and Mentor® MemoryGel™ Xtra showed no postoperative complications. However, the BellaGel® SmoothFine, Sebbin® Sublimity and BellaGel® Smooth showed incidences of 8.87%, 4.84% and 1.61%, respectively. A subgroup analysis also showed differences in incidences of postoperative complications between microtextured and smooth breast implants (15.18% vs. 16.67%). Conclusions: In conclusion, our results indicate that diverse types of an SGBI are commercially available and their safety profile varies according to the manufacturer. Plastic surgeons should consider the safety profile of each device in selecting the optimal types of the device for Korean women who are in need of an implant-based augmentation mammaplasty. However, this warrants a single-surgeon, single-center study with long periods of follow-up.

Time-domain room acoustic simulations with extended-reacting porous absorbers using the discontinuous Galerkin method.

This paper presents an equivalent fluid model (EFM) formulation in a three-dimensional time-domain discontinuous Galerkin finite element method framework for room acoustic simulations. Using the EFM allows for the modeling of the extended-reaction (ER) behavior of porous sound absorbers. The EFM is formulated in the numerical framework by using the method of auxiliary differential equations to account for the frequency dependent dissipation of the porous material. The formulation is validated analytically and an excellent agreement with the theory is found. Experimental validation for a single reflection case is also conducted, and it is shown that using the EFM improves the simulation accuracy when modeling a porous material backed by an air cavity as compared to using the local-reaction (LR) approximation. Last, a comparative study of different rooms with different porous absorbers is presented, using different boundary modeling techniques, namely, a LR approximation, a field-incidence (FI) approximation, or modeling the full ER behavior with the EFM. It is shown that using a LR or FI approximation leads to large and perceptually noticeable errors in simulated room acoustic parameters. The average T20 reverberation time error is 4.3 times the just-noticeable-difference (JND) threshold when using LR and 2.9 JND when using FI.

Bayesian decay time estimation in a reverberation chamber for absorption measurements.

This work investigates the use of the initial decay time to obtain the Sabine absorption coefficient from measurements conducted in a reverberation chamber. Due to non-uniform distribution of sound absorption in the test chamber, measured energy decay functions exhibit multiple slopes, which cannot be evaluated unambiguously using linear regression as prescribed in the current standard (ISO 354, International Organization for Standardization, Geneva, Switzerland, 2003). As an alternative, this study proposes a Bayesian framework that allows estimating multiple decay parameters, hence capturing more accurately the energy decay features. Measurements are carried out in a reverberation chamber with and without diffusing elements to investigate the influence of diffusers on the absorption coefficient and on the decay process. Measured absorption coefficients of a porous sample are compared to theoretical values estimated with a transfer matrix model. The results show that the Sabine absorption coefficient calculated using the shortest decay time agrees well with the size-corrected theoretical absorption coefficient.

Characterization of sound scattering using near-field pressure and particle velocity measurements.

The acoustic properties of surfaces are commonly evaluated using samples of finite size, which generate edge diffraction effects that are often disregarded. This study makes use of sound scattering theory to characterize such finite samples. In a given sound field, the samples can be described by a unique complex directivity function called the far-field pattern. Numerical results show that the far-field pattern contains extensive information on the tested samples, including sound absorption and surface scattering, as well as scattering due to finiteness. In this paper, a method is introduced to estimate the far-field pattern of a finite sample. The method relies on measurements of the sound pressure and acoustic particle velocity in the near-field of the sample, and it makes use of the Helmholtz integral equation. The proposed technique is examined in an anechoic room where the sound field near the test sample is scanned with a three-dimensional sound intensity probe. The estimated far-field pattern is compared with numerical predictions up to 1 kHz.

Time domain room acoustic simulations using the spectral element method.

This paper presents a wave-based numerical scheme based on a spectral element method, coupled with an implicit-explicit Runge-Kutta time stepping method, for simulating room acoustics in the time domain. The scheme has certain features which make it highly attractive for room acoustic simulations, namely (a) its low dispersion and dissipation properties due to a high-order spatio-temporal discretization; (b) a high degree of geometric flexibility, where adaptive, unstructured meshes with curvilinear mesh elements are supported; and (c) its suitability for parallel implementation on modern many-core computer hardware. A method for modelling locally reacting, frequency dependent impedance boundary conditions within the scheme is developed, in which the boundary impedance is mapped to a multipole rational function and formulated in differential form. Various numerical experiments are presented, which reveal the accuracy and cost-efficiency of the proposed numerical scheme.

Near-Road Air Pollutant Measurements: Accounting for Inter-Site Variability Using Emission Factors.

A daily integrated emission factor (EF) method was applied to data from three near-road monitoring sites to identify variables that impact traffic related pollutant concentrations in the near-road environment. The sites were operated for 20 months in 2015-2017, with each site differing in terms of design, local meteorology, and fleet compositions. Measurement distance from the roadway and local meteorology were found to affect pollutant concentrations irrespective of background subtraction. However, using emission factors mostly accounted for the effects of dilution and dispersion, allowing intersite differences in emissions to be resolved. A multiple linear regression model that included predictor variables such as fraction of larger vehicles (>7.6 m in length; i.e., heavy-duty vehicles), vehicle speed, and ambient temperature accounted for intersite variability of the fleet average NO, NO x, and particle number EFs (R2:0.50-0.75), with lower model performance for CO and black carbon (BC) EFs (R2:0.28-0.46). NO x and BC EFs were affected more than CO and particle number EFs by the fraction of larger vehicles, which also resulted in measurable weekday/weekend differences. Pollutant EFs also varied with ambient temperature and because there were little seasonal changes in fleet composition, this was attributed to changes in fuel composition and/or post-tailpipe transformation of pollutants.

Improvement of biosynthesis and accumulation of bioactive compounds by elicitation in adventitious root cultures of Polygonum multiflorum.

We examined the effects of abiotic (methyl jasmonate [MeJA] and salicylic acid [SA]) and biotic (yeast extract and chitosan) elicitors for improvement of bioactive compounds production on adventitious root cultures in Polygonum multiflorum. The application of yeast extract resulted in significantly (p ≤ 0.05) higher dry root biomass (9.98 g/L) and relative growth rate versus the control. Cultures treated with abiotic elicitors showed higher percentage of dry weight than the other samples. Low concentrations of all elicitors (50 µM MeJA and SA, and 50 mg/L yeast extract) improved secondary metabolite production except for chitosan, whose performance was worse than that of the control. HPLC analysis of various bioactive compounds revealed significantly higher elicitation efficiency for MeJA than for the other treatments, with an approximately 2-fold increase in root dry weight (22.08 mg/g DW) under 50 µM MeJA treatment versus the control (10.35 mg/g DW). We also investigated the feasibility of scaling up the production process by comparing shake flask cultures with 3- and 5-L balloon type bubble bioreactors (BTBB) using 50 µM MeJA as an elicitor. Growth and metabolite accumulation increased in BTBB compared with shake flask cultures. We detected a non-significant difference in biomass productivity between 3 and 5-L BTBB, but the efficiency of bioactive compound accumulation decreased with increasing volume. These findings will be useful for developing a pilot-scale P. multiflorum adventitious root cultivation process for high biomass and bioactive compound production to meet the demands for natural ingredients by the pharmaceutical and cosmetic industries without affecting the natural habitat of this plant.

Prediction of sound absorption based on specific airflow resistance and air permeability of textiles.

Both specific airflow resistance and air permeability can be used as a parameter to estimate the sound absorption of textiles. The measurement of specific airflow resistance is specified in ISO 9053 (Int. Standards Org., 1991), but it is known to be inaccurate for low specific airflow resistance. This paper compares the measured specific airflow resistance according to ISO 9053 and those calculated from air permeability according to ISO 9237 (Int. Standards Org., 1995). The sound absorption coefficients predicted by Pieren's model [R. Pieren, Textile Res. J. 82(9), 864-874 (2012)] are compared with measurements by the impedance tube method, which concludes that those predicted from the air permeability are more accurate than those from the measured specific airflow resistance for textiles.

A wavenumber approach to quantifying the isotropy of the sound field in reverberant spaces.

This study proposes an experimental method for evaluating isotropy in enclosures, based on an analysis of the wavenumber spectrum in the spherical harmonics domain. The wavenumber spectrum, which results from expanding an arbitrary sound field into a plane-wave basis, is used to characterize the spatial properties of the observed sound field. Subsequently, the obtained wavenumber spectrum is expanded into a series of spherical harmonics, and the moments from this spherical expansion are used to characterize the isotropy of the wave field. The analytical framework is presented. The method is examined numerically and experimentally, based on array measurements in four chambers: two anechoic chambers (one with a single source and another with an array of 52 sources), a reverberation chamber, and the same reverberation chamber with a sample of absorbing material on the floor. The results indicate that the proposed methodology is suitable for assessing the isotropy of a sound field.

AINTEGUMENTA and AINTEGUMENTA-LIKE6/PLETHORA3 Induce LEAFY Expression in Response to Auxin to Promote the Onset of Flower Formation in Arabidopsis.

Proper timing of the onset to flower formation is critical for reproductive success. Monocarpic plants like Arabidopsis (Arabidopsis thaliana) switch from production of branches in the axils of leaves to that of flowers once in their lifecycle, during the meristem identity transition. The plant-specific transcription factor LEAFY (LFY) is necessary and sufficient for this transition. Previously, we reported that the plant hormone auxin induces LFY expression through AUXIN RESPONSE FACTOR5/MONOPTEROS (ARF5/MP). It is not known whether MP is solely responsible for auxin-directed transcriptional activation of LFY. Here, we show that two transcription factors belonging to the AINTEGUMENTA-LIKE/PLETHORA family, AINTEGUMENTA (ANT) and AINTEGUMENTA-LIKE6/PLETHORA3 (AIL6/PLT3), act in parallel with MP to upregulate LFY in response to auxin. ant ail6 mutants display a delay in the meristem identity transition and in LFY induction. ANT and AIL6/PLT3 are expressed prior to LFY and bind to the LFY promoter to control LFY mRNA accumulation. Genetic and promoter/reporter studies suggest that ANT/AIL6 act in parallel with MP to promote LFY induction in response to auxin sensing. Our study highlights the importance of two separate auxin-controlled pathways in the meristem identity transition.

Influence of polymer architectures on diffusion in unentangled polymer melts.

Recent simulations have indicated that the thermodynamic properties and the glassy dynamics of polymer melts are strongly influenced by the average molecular shape, as quantified by the radius of gyration tensor of the polymer molecules, and that the average molecular shape can be tuned by varying the molecular topology (e.g., ring, star, linear chain, etc.). In the present work, we investigate if the molecular shape is similarly a predominant factor in understanding the polymer center of mass diffusion D in the melt, as already established for polymer solutions. We find that all our D data for unentangled polymer melts having a range of topologies can be reasonably described as a power law of the polymer hydrodynamic radius, Rh. In particular, this scaling is similar to the scaling of D for a tracer sphere having a radius on the order of the chain radius of gyration, Rg. We conclude that the chain topology influences the molecular dynamics in as much as the polymer topology influences the average molecular shape. Experimental evidence seems to suggest that this situation is also true for entangled polymer melts.