bluuebunny/crossref_metadata_2025 huggingface dataset:
The effectiveness of translation technology training: a mixed methods study
Authors: Su Wenchao , Li Defeng
Published: September 2023

Translation technology is nowadays widely used by many language service sectors, and translation technology training is offered by many universities and institutions around the world. However, the effectiveness of translation technology training is yet to be explored. To fill this gap, we conducted a questionnaire survey of 385 Master of Translation and Interpreting (MTI) students in China to understand the general trends in their reception and perception of their translation technology courses. In order to probe into the student’s experience of taking these courses, we further interviewed 8 of them. All the interviews, semi-structured to allow for both structured and free expression, were recorded and transcribed verbatim for analysis. The Kirkpatrick model was used as the evaluation framework of training effectiveness. Results show that some students felt that the training was quite effective and it enabled them to gain the knowledge of computer-assisted translation tools. However, some felt less positive about the effectiveness of current training of translation technology and cited various challenges they encountered in their learning. All the findings and recommendations thereof will be discussed. It is hoped that the findings will contribute to our understanding and improvement of translation technology training in future programs.
Experimental and Semiclassical Stark Widths and Shifts for Spectral Lines of Neutral and Ionized Atoms (A Critical Review of Experimental and Semiclassical Data for the Period 2008 Through 2020)
Authors: Djurović S. , Blagojević B. , Konjević N.
Published: September 2023

This Review Article compares new experimental and corresponding semiclassical Stark broadened data for non-hydrogenic spectral lines of neutral atoms and positive ions. This Review covers the period 2008 until the end of 2020 and presents the continuation of previous critical reviews from 1976 (two), 1984 (two), 1990, 2002, and one from 2009. This Review reports the Stark broadening parameters of 1665 spectral lines belonging to 35 elements with 61 different atomic and ion species. The data are taken from 60 papers. Experimental data are arranged by elements and spectra, and these are reported in tables in alphabetical and numerical order, respectively. Each experimental Stark broadening parameter is followed with estimated accuracy. The experimental Stark broadening and shift data presented in the tables are compared with the corresponding semiclassical results available in the literature. In addition, for comparison experiments versus semiclassical theoretical Stark broadening parameters, a numerically improved theoretical approach developed based on Griem and co-workers’ theory is used to evaluate Stark widths and shifts of all studied lines whenever required atomic energy levels data and transition probabilities are available. At the end of the text report, for each analyzed neutral or ion species, the information about the location of the same species data in preceding reviews is given.
Defect evolution of iodine vacancy and related strain modulation in all-inorganic halide perovskites
Authors: Xu Xin , Cai Yating , Qu Yating , Li Ang , Gao Yujia , Huang Tengcheng , Wu Zhuxia , Huang Xi , Zhang Zheyu , Wu Zhenyuan , Shi Tingting , Xie Weiguang , Liu Pengyi
Published: September 2023

Vacancy related defects play a crucial role in optoelectronic properties and carrier transport for photovoltaic materials, especially for its structural evolution becoming non-radiative defects induced by strain. Thus far, the evolution phenomena of vacancy defects in halide perovskite triggered by energy or strain have not been systematically investigated. Herein, we study the change in defect levels occurred in different inorganic perovskite systems and the situation caused by strain in varied strength based on density functional theory calculations. We discover that VI deep levels are easily transformed from shallow levels due to the formation of Pb–Pb dimers and octahedral distortion in all-inorganic perovskites, especially in CsPbI3. Moreover, strain can be quantitatively applied to control the suppression or enhancement of the formation of dimer in CsBI3 (B = Pb/Ge) perovskites. Eventually, our calculation results unravel that the defect physics of VI defect and the formation mechanism of non-radiative center in all inorganic perovskites, which depends on the strain strength and the accompanying octahedral distortion. The strain modulation and its quantitation effect on defect evolution of dominant vacancy map a pioneering route toward fabricating high performance inorganic photovoltaics.
Terahertz integration platforms using substrateless all-silicon microstructures
Authors: Headland Daniel , Fujita Masayuki , Carpintero Guillermo , Nagatsuma Tadao , Withayachumnankul Withawat
Published: September 2023

The absence of a suitable standard device platform for terahertz waves is currently a major roadblock that is inhibiting the widespread adoption and exploitation of terahertz technology. As a consequence, terahertz-range devices and systems are generally an ad hoc combination of several different heterogeneous technologies and fields of study, which serves perfectly well for a once-off experimental demonstration or proof-of-concept, but is not readily adapted to real-world use case scenarios. In contrast, establishing a common platform would allow us to consolidate our design efforts, define a well-defined scope of specialization for “terahertz engineering,” and to finally move beyond the disconnected efforts that have characterized the past decades. This tutorial will present arguments that nominate substrateless all-silicon microstructures as the most promising candidate due to the low loss of high-resistivity float-zone intrinsic silicon, the compactness of high-contrast dielectric waveguides, the designability of lattice structures, such as effective medium and photonic crystal, physical rigidity, ease and low cost of manufacture using deep-reactive ion etching, and the versatility of the many diverse functional devices and systems that may be integrated. We will present an overview of the historical development of the various constituents of this technology, compare and contrast different approaches in detail, and briefly describe relevant aspects of electromagnetic theory, which we hope will be of assistance.
Investigations on the wave performance of Savonius turbine operating under initial phase-locked strategy
Authors: Li Fengshen , Yao Jianjun , Eskilsson Claes , Pan Youcheng , Chen Junhua , Ji Renwei
Published: September 2023

Savonius hydrokinetic turbines (SHTs), categorized as emerging cyclic-type wave energy converters (WECs), have demonstrated notable potential in achieving elevated energy conversion efficiency and consistent power output. This performance is particularly observed when operating under the initial phase-locked strategy (IPLS), marking a significant advancement in the realm of wave energy harvesting. However, a thorough exploration of the influences stemming from wave conditions and turbine design remains an area that warrants further investigation for advancing the performance of SHT-WECs under the proper operational strategy. This study undertakes an exhaustive analysis of geometric parameters, encompassing turbine diameter, blade number, and thickness. An experiment-validated numerical model based on the unsteady two-phase Reynolds-averaged Navier–Stokes equations is adopted in the research. Comprehensive investigations include analyses of flow fields around the turbine, pressure distributions on blade surfaces, and dynamic torque variations. These analyses serve to elucidate the variation rules of hydrodynamic characteristics and their influential mechanisms. The results highlight the notable impact of the proposed “relative-short wavelength impact” on the performance of SHT-WECs operating under IPLS conditions. Notably, no significant impact is observed when the relative wavelength exceeds 17. Optimal performance is achieved with the thinnest and two-bladed turbine configuration. Moreover, optimizing the turbine diameter significantly enhances SHT-WEC conversion efficiency, with the attained maximum value reaching approximately 18.6%. This study offers a concise guideline for designing turbine diameters in alignment with specific wave conditions.
Discharge characteristics of an atmospheric pulsed microwave Ar/CF4 plasma jet
Authors: Wang Longzhen , Liu Changhong , Wu Jie , Hu Xiaoyu , Chen Sile , Cheng Tao , Lu Haoran , Chen Zhaoquan
Published: September 2023

The atmospheric fluorocarbon plasma is widely used in surface modification of polymers. Recently, the pulsed microwave Ar/CF4 plasma jet is proved to be a promising atmospheric fluorocarbon plasma source with good performance. In this paper, the discharge characteristics of the pulsed microwave Ar/CF4 plasma jet are studied systematically. The discharge morphologies, ionization processes, optical emission spectra, and electron densities are obtained by a digital camera, an intensified charge coupled device, a fiber spectrometer, and a home-made microwave Rayleigh scattering device, respectively. The influences of the plasma operation parameters on the discharge characteristics are investigated, and the microwave input power and CF4 volume fraction are optimized. The results provide a basis for the generation and surface modification application of high-performance atmospheric fluorocarbon plasma.
All-solid integratable device of electric field control of magnetism based on hydrogen ion migration in La1−xSrxMnO3
Authors: Liu Weikang , Wu Xinyi , Wu Shuyun , Zhao Xiangxiang , Miao Tingting , Chu Ruiyue , Cui Bin , Cheng Bin , Liu Liang , Hu Jifan
Published: September 2023

Field-effect transistors based on semiconductor integration technology have come to a bottleneck, while electric field control of magnetism has great potential for applications in next-generation magnetic memory and calculators based on electron spins. Magnetic properties manipulation from a mechanism of ion migration driven by an electric field has the advantages of low energy consumption, nonvolatility, reproducibility, and durability. Here, we introduce a solid-state integratable hydrogen ion storage electrolyte silicon phosphate as the gate to achieve reversible control of magnetoresistance, magnetism, and magnetic interaction in the La1−xSrxMnO3/SrTiO3 ferromagnetic system. The controllable double-exchange interaction and spin scattering mechanism sketch the theoretical physical picture for these results. This work is expected to open up additional opportunities in the translation of electric control of magnetism into practical applications.
Effect of wavy leading edges on airfoil tonal noise
Authors: Chen Weijie , Wang Xingyu , Xing Yudi , Wang Liangfeng , Qiao Weiyang
Published: September 2023

This work presents numerical studies on the effect of wavy leading edges on airfoil instability tonal noise. Large eddy simulations are conducted for NACA0012 (National Advisory Committee for Aeronautics) airfoils with straight and wavy leading edges. The far-field aerodynamic noise is predicted using the Ffowcs Williams and Hawkings acoustic analogy theory. The inflow Mach number is approximately 0.17 with an angle of attack of 4.3°, and the chord based Reynolds number is 600 000. The present numerical method is first validated by existing numerical results and a semi-empirical model for the straight baseline airfoil. Then, the effects of wavy leading edges on the aerodynamic performance, aeroacoustic performance, and noise reduction mechanisms are discussed in detail. The wavy leading edge is found to be detrimental to the mean aerodynamic performance with a decreased lift and increased drag. However, the lift fluctuations are significantly reduced. The instability tonal noise and its harmonic are totally removed by the wavy leading edges, while an extra broadband hump appears at the middle frequency. The low frequency and high frequency noise are also increased by the wavy airfoil. The laminar separation bubble is removed, and the flow separation is decreased by the wavy airfoil in the vicinity of the trailing edge. The pressure fluctuations around the trailing-edge are considerably diminished, and the spanwise coherence spectra are also significantly reduced by the wavy airfoil. Furthermore, it is noteworthy that the coherence reduction spectrum at the source is almost consistent with the far-field noise reduction spectrum.
Jetting to dripping in compound liquid jets falling under gravity
Authors: Afzaal Muhammad F. , Uddin Jamal
Published: September 2023

In recent years, there has been a substantial growth in technologies, which exploits the disintegration of a compound thread of fluid to produce compound droplets or capsules. In many cases, careful control of the relevant operating and material parameters can determine a range of features, including capsule sizes, production rates, and wastage. In this paper, we investigate the transition between jetting and dripping of a compound inviscid liquid jet falling under gravity in a surrounding gas. We derive an analytical expression for the dispersion relation, which takes into account the non-uniform nature of the jet, which we then solve numerically utilizing the cusp map method and its significant reduction in computational effort required in identifying saddle points of the dispersion relation. Particular attention is paid to investigating the effects of the inner-to-outer surface tension ratio σ and initial jet radii, χ, as well as the influence of gravity on critical Weber numbers, Wec (which mark the transition between jetting and dripping). Our results provide the convective to absolute instability boundary for a number of different parameter values.
The impact of COVID-19 on community mental health: lessons learned from Tasmania, Australia
Authors: Savaglio Melissa , O’Donnell Renee , Skouteris Helen
Published: September 2023

Background The COVID-19 pandemic had a significant impact on community mental health globally and widened pre-existing health and social inequities. Tasmania, Australia has one of the highest rates of mental ill health and socioeconomic disadvantage in the country. Whilst Tasmania experienced a delayed and reduced physical presence of COVID-19 compared to other states and territories, mental health impacts remain. It is necessary to understand such impacts to inform policy, practice, and recommendations to enhance the mental health service sector and prevent future mental health burden. This qualitative study aimed to explore expert mental health stakeholders’ perspectives of the impact of COVID-19 on: (1) the mental health of people living in Tasmania, and (2) mental health services. Method Semi-structured interviews with 12 expert mental health stakeholders across Tasmania were conducted. This sample was well-positioned to comment on the impact of COVID-19 on community mental health and provide recommendations to enhance the sector. Interviews were thematically analysed. Results Three subthemes exploring the COVID-19 impact on mental health were included: (1) anxiety, distress, and isolation; (2) varying presentations across age groups; and (3) increased complexity. Four key themes capturing the COVID-19 impact on mental health services were identified: (1) transition to telehealth; (2) increased service demand; (3) spotlight on service gaps; and (4) local workforce shortages. Conclusions The pandemic has highlighted existing gaps across the community mental health service sector, and exacerbated existing psychosocial/structural stressors resulting in increased presentations and complexity of mental illness among the community, particularly for youth. Existing treatment gaps and inequities in service access, engagement, and mental health outcomes will persist if not addressed. Recommendations have been provided to inform community mental health service planning, policy, design, access, and provision, and improve wellbeing.
In situ carbon and nitrogen turnover dynamics in topsoils: a climate warming simulation study in an alpine ecosystem
Authors: Djukic I. , Zehetner F. , Horacek M. , Gerzabek M. H.
Published: September 2023

Context Climate change may affect ecosystem carbon (C) and nitrogen (N) cycling by accelerating C and N transformations in soil, which in turn can feed back to the climate system. These effects may be especially pronounced in cold regions, which are particularly sensitive to climate change, store significant amounts of soil organic C and harbour N-poor ecosystems. Still it is debated how C and N dynamics in high-elevation ecosystems will respond to rising temperatures. Aims We investigated the effects of climate warming and shifting vegetation zones on litter C and N turnover in a high-elevation ecosystem of the Austrian Alps. Methods We used high-to-low elevation soil translocation to simulate the combined effects of changing climatic conditions and shifting vegetation zones, and combined this with an in-situ decomposition experiment using 13C and 15N double-labelled litter material. Key results In our experiment, plant litter decomposition raised soil pH by up to one pH unit (5.7 to 6.7) within 15–20 weeks, followed by a decrease below the initial pH values until the end of the experiment. Simulated mean annual soil warming of 1.5 and 2.7°C resulted in a significantly accelerated turnover of added maize-C, whereas maize-N persisted longer in the soils. The more resistant C pool (half-life 1–2 years) responded much more strongly to experimental warming (100–190% increase in decomposition rate) compared to the labile pool (half-life 1–2 weeks; 5–20% increase in decomposition rate). In contrast, simulated warming led to a significant decrease of N loss by mineralisation for both pools (change in half-life for labile maize straw N pool, 5.9 to 10.5 and 19.1  days, respectively; and stabile maize straw N pool, 1386 to 1733 and 3466 days, respectively). Conclusions Our results show that rising temperatures in alpine ecosystems may have contrasting effects on C and N dynamics in the short to medium term. This reflects very tight N cycling and underlines the importance of soil hydrological processes, such as water percolation and leaching, on the fate of N in such N-poor ecosystems. Implications The linkage between N cycling and soil hydrological processes should be accounted for in ecosystem modelling efforts.
Void-free interface between in and high-impurity Cu joint
Authors: Lee Jia-Yi , Shen Yu-An , Chen Chih-Ming
Published: September 2023

The effect of impurities in the Cu film on the void formation at the interface of the Sn-rich solder joint has been extensively studied. However, this has rarely been studied for In solder joints. In this study, Sn-3.0Ag-0.5Cu (SAC305) and In-solder/ Cu films with high impurities were aged at 150 °C to analyze the films at various aging times. A metastable CuIn2 phase appeared and transformed into a stable Cu11In9 phase. Noticeable voids and cracks were observed at the SAC305/Cu interface during the solid-state aging. In contrast, there was a void-free interface between In and Cu-CP. This was primarily due to the difference in diffusion behaviour between In/Cu and SAC305/Cu. The mechanism of the above phenomenon was revealed.
Resonant Scattering of Gravitational Waves with Electromagnetic Waves
Authors: Yan 闫 Ruodi 若帝 , Lau 刘 Yun Kau 润球
Published: September 2023

A certain class of exact solutions of Einstein Maxwell spacetime in general relativity is discussed to demonstrate that at the level of theory, when certain parametric resonance condition is met, the interaction of electromagnetic field with a gravitational wave will display certain Lyapunov instability and lead to exponential amplification of a gravitational wave train described by certain Newman–Penrose component of the Weyl curvature. In some way akin to a free electron laser in electromagnetic theory, by the conversion of electromagnetic energy into gravitational energy in a coherent way, the feasibility of generating a pulsed-laser-like intense beam of gravitational wave is displayed.
Remaining useful life prediction of lithium-ion batteries using EM-PF-SSA-SVR with gamma stochastic process
Authors: Keshun You , Guangqi Qiu , Yingkui Gu
Published: September 2023

Due to the complex changes in physicochemical properties of lithium-ion batteries during the process from degradation to failure, it is difficult for methods based on physical or data-driven models to fully characterize this nonlinear process, and existing methods that hybridize physical and data-driven models suffer from ambiguous hybridization, which results in the vast majority of existing methods for predicting the remaining useful life (RUL) of lithium-ion batteries suffering from a lack of accuracy and robustness. In this study, a novel hybrid approach based on empirical modeling and data-driven techniques is proposed for predicting the RUL of lithium-ion batteries. To better capture its complexity, stochasticity, and state transition, and improve the modeling accuracy and RUL prediction precision, Gamma stochasticity and state-space modeling are used to empirically model the complex Li-ion battery degradation process. Moreover, the expectation maximization (EM) method of particle filtering (PF) was used to estimate the hidden parameters of the empirical model, and the estimated parameters were corrected using an optimized support vector regression (SVR) method to enhance the generalization performance and robustness of the data-driven model. The results show that the gamma state-space model is effective in capturing the inherent stochastic properties of the battery degradation and the proposed hybrid method outperforms the existing prediction methods in RUL prediction. The experiments show that the sparrow search algorithm (SSA) optimized SVR is considered to be the most effective correction method for the estimated parameters, while the new EM-PF-SSA-SVR hybrid method provides better performance for state assessment and RUL prediction of lithium-ion batteries. It is indicated that the proposed EM-PF-SSA-SVR method with Gamma stochastic process has hybrid validity and superior performance with equal performance and less parameter computation relative to the existing state-of-the-art deep learning RUL prediction methods.
Mechanical fault diagnosis of gas-insulated switchgear based on saliency feature of auditory brainstem response under noise background
Authors: Ji Haitao , Liu Houguang , Wang Jie , Yuan Guogang , Yang Jianhua , Yang Shanguo
Published: September 2023

The mechanical fault of gas-insulated switchgear (GIS) seriously threatens the security of the power grid. Recently, acoustic-based fault diagnosis methods, which have the advantage of non-contact measurement, have been applied to the GIS mechanical fault diagnosis, but vulnerable to the interference of the background noise. To improve the capacity of the acoustic-based GIS fault diagnosis under noise background, by simulating the sound feature extraction ability and anti-noise ability of human auditory system, a novel GIS mechanical fault diagnosis method based on saliency feature of auditory brainstem response (SFABR) is proposed. First, an auditory saliency model, which considers both the auditory periphery and the auditory nerve center was constructed by combining the deep auditory model and the saliency model. After processing GIS emitted acoustic signal, the auditory brainstem response (ABR) was obtained, and the saliency features of the ABR were extracted to obtain the SFABR. Then, the characteristic frequency distribution of the auditory saliency model was adjusted to make it more suitable for the spectral characteristics of the GIS sound signal. Finally, the SFABR was mapped to a two-dimensional CNN to train a model for GIS mechanical fault diagnosis. This method simulates the process of auditory response extraction and the selection effect of auditory attention on sound elements. The 110 kV three-phase GIS fault simulation experiment shows that for GIS mechanical faults, the diagnosis method based on SFABR can obtain 96.1% fault identification accuracy. In different noise environments, compared with the traditional acoustic-based fault diagnosis methods, this method has stronger anti-noise performance, and can more effectively realize the identification of GIS mechanical failure types. In future research, the method can be further extended to fault diagnosis of more types of power equipment.
Compressed AFM-IR hyperspectral nanoimaging
Authors: Kästner B , Marschall M , Hornemann A , Metzner S , Patoka P , Cortes S , Wübbeler G , Hoehl A , Rühl E , Elster C
Published: September 2023

Infrared (IR) hyperspectral imaging is a powerful approach in the field of materials and life sciences. However, for the extension to modern sub-diffraction nanoimaging it still remains a highly inefficient technique, as it acquires data via inherent sequential schemes. Here, we introduce the mathematical technique of low-rank matrix reconstruction to the sub-diffraction scheme of atomic force microscopy-based infrared spectroscopy (AFM-IR), for efficient hyperspectral IR nanoimaging. To demonstrate its application potential, we chose the trypanosomatid unicellular parasites Leishmania species as a realistic target of biological importance. The mid-IR spectral fingerprint window covering the spectral range from 1300 to 1900 cm−1 was chosen and a distance between the data points of 220 nm was used for nanoimaging of single parasites. The method of k-means cluster analysis was used for extracting the chemically distinct spatial locations. Subsequently, we randomly selected only 10% of an originally gathered data cube of 134 (x) × 50 (y) × 148 (spectral) AFM-IR measurements and completed the full data set by low-rank matrix reconstruction. This approach shows agreement in the cluster regions between full and reconstructed data cubes. Furthermore, we show that the results of the low-rank reconstruction are superior compared to alternative interpolation techniques in terms of error-metrics, cluster quality, and spectral interpretation for various subsampling ratios. We conclude that by using low-rank matrix reconstruction the data acquisition time can be reduced from more than 14 h to 1–2 h. These findings can significantly boost the practical applicability of hyperspectral nanoimaging in both academic and industrial settings involving nano- and bio-materials.
3D phantom for image quality assessment of mammography systems
Authors: Bermúdez J , Roque G , Calderón J , Pardo P , Sánchez M , Ramos V , Ávila C
Published: September 2023

Objective. To present an innovative approach for the design of a 3D mammographic phantom for medical equipment quality assessment, estimation of the glandular tissue percentage in the patient’s breast, and emulation of microcalcification (μC) breast lesions. Approach. Contrast-to noise ratio (CNR) measurements, as well as spatial resolution and intensity-to-glandularity calibrations under mammography conditions were performed to assess the effectiveness of the phantom. CNR measurements were applied to different groups of calcium hydroxyapatite (HA) and aluminum oxide (AO) μCs ranging from 200 to 600 μm. Spatial resolution was characterized using an aluminum plate contained in the phantom and standard linear figures of merit, such as the line spread function and modulation transfer function (MTF). The intensity-to-glandularity calibration was developed using an x-ray attenuation matrix within the phantom to estimate the glandular tissue percentage in a breast with a compressed thickness of 4 cm. Main results. For the prototype studied, the minimum confidence level for detecting HA μCs is 95.4%, while for AO μCs is above 68.3%. It was also possible to determine that the MTF of the commercial mammography machine used for this study at the Nyquist frequency is 41%. Additionally, a one-to-one intensity-to-glandularity calibration was obtained and verified with Monte-Carlo simulation results. Significance. The phantom provides traditional arrangements presented in accreditation phantoms, which makes it competitive with available devices, but excelling in regarding affordability, modularity, and inlays distribution. Moreover, its design allows to be positioned in close proximity to the patient's breast during a medical screening for a simultaneous x-ray imaging, such that the features of the phantom can be used as reference values to specify characteristics of the real breast tissue, such as proportion of glandular/adipose composition and/or μC type and size lesions.
Uncertainty quantification of the effect of cardiac position variability in the inverse problem of electrocardiographic imaging
Authors: Bergquist Jake A , Zenger Brian , Rupp Lindsay C , Busatto Anna , Tate Jess , Brooks Dana H , Narayan Akil , MacLeod Rob S
Published: September 2023

Objective. Electrocardiographic imaging (ECGI) is a functional imaging modality that consists of two related problems, the forward problem of reconstructing body surface electrical signals given cardiac bioelectric activity, and the inverse problem of reconstructing cardiac bioelectric activity given measured body surface signals. ECGI relies on a model for how the heart generates bioelectric signals which is subject to variability in inputs. The study of how uncertainty in model inputs affects the model output is known as uncertainty quantification (UQ). This study establishes develops, and characterizes the application of UQ to ECGI. Approach. We establish two formulations for applying UQ to ECGI: a polynomial chaos expansion (PCE) based parametric UQ formulation (PCE-UQ formulation), and a novel UQ-aware inverse formulation which leverages our previously established ‘joint-inverse’ formulation (UQ joint-inverse formulation). We apply these to evaluate the effect of uncertainty in the heart position on the ECGI solutions across a range of ECGI datasets. Main results. We demonstrated the ability of our UQ-ECGI formulations to characterize the effect of parameter uncertainty on the ECGI inverse problem. We found that while the PCE-UQ inverse solution provided more complex outputs such as sensitivities and standard deviation, the UQ joint-inverse solution provided a more interpretable output in the form of a single ECGI solution. We find that between these two methods we are able to assess a wide range of effects that heart position variability has on the ECGI solution. Significance. This study, for the first time, characterizes in detail the application of UQ to the ECGI inverse problem. We demonstrated how UQ can provide insight into the behavior of ECGI using variability in cardiac position as a test case. This study lays the groundwork for future development of UQ-ECGI studies, as well as future development of ECGI formulations which are robust to input parameter variability.
Non-local and non-Hermitian acoustic metasurfaces
Authors: Wang Xu , Dong Ruizhi , Li Yong , Jing Yun
Published: September 2023

Acoustic metasurfaces are at the frontier of acoustic functional material research owing to their advanced capabilities of wave manipulation at an acoustically vanishing size. Despite significant progress in the last decade, conventional acoustic metasurfaces are still fundamentally limited by their underlying physics and design principles. First, conventional metasurfaces assume that unit cells are decoupled and therefore treat them individually during the design process. Owing to diffraction, however, the non-locality of the wave field could strongly affect the efficiency and even alter the behavior of acoustic metasurfaces. Additionally, conventional acoustic metasurfaces operate by modulating the phase and are typically treated as lossless systems. Due to the narrow regions in acoustic metasurfaces’ subwavelength unit cells, however, losses are naturally present and could compromise the performance of acoustic metasurfaces. While the conventional wisdom is to minimize these effects, a counter-intuitive way of thinking has emerged, which is to harness the non-locality as well as loss for enhanced acoustic metasurface functionality. This has led to a new generation of acoustic metasurface design paradigm that is empowered by non-locality and non-Hermicity, providing new routes for controlling sound using the acoustic version of 2D materials. This review details the progress of non-local and non-Hermitian acoustic metasurfaces, providing an overview of the recent acoustic metasurface designs and discussing the critical role of non-locality and loss in acoustic metasurfaces. We further outline the synergy between non-locality and non-Hermiticity, and delineate the potential of using non-local and non-Hermitian acoustic metasurfaces as a new platform for investigating exceptional points, the hallmark of non-Hermitian physics. Finally, the current challenges and future outlook for this burgeoning field are discussed.
Design of continuously tunable varifocal metalenses
Authors: Yang Fan , Dao Khoi Phuong , An Sensong , Qiu Xiaoming , Zhang Yifei , Hu Juejun , Gu Tian
Published: September 2023

Active metasurfaces with tunable optical properties enable reconfigurable or programmable photonic systems that can swiftly adapt to different functional needs. Realizing continuous tuning of phase-gradient metasurfaces, however, remains elusive. This is because active modulation of individual or few meta-atoms is traditionally deemed essential to continuous tuning, which nonetheless introduces significant technical difficulties associated with addressing and control of large meta-atom arrays. In this paper, we propose a novel active metasurface architecture to circumvent this challenge. The key notion is to modulate the gradients of metasurface phase profiles over large regions instead of setting the phase at individual locations, thereby enabling continuous tuning with only a minimal number of independently controlled elements. The design principle can be generically applied to different active tuning mechanisms. As an example, we modeled a varifocal metalens with focal length continuously tunable between 4 and 10 mm based on electrically switched optical phase change materials.
Optimal power flow solution using opposition based modified Rao’s algorithm
Authors: Shaik Mabhu Jani , Kottala Padma , Rama Sudha K
Published: September 2023

Optimal Power flow (OPF) is crucial in a power system, and this is essential for continuous monitoring of the system’s current status, system stability, extension of the system, best operation of the system, etc. This paper applies Particle Swarm Optimization (PSO) and proposed Opposition-based Modified Rao’s (OMR) algorithms for OPF solutions with various technical constraints. In this paper, the objectives are to minimize the total generation cost, total real power loss, sum of squared voltage stability index, and total voltage deviation and to know performance parameters in terms of real and reactive power flows, voltage profile, load bus voltage deviations, load angle and voltage stability indices. To see the effectiveness of the proposed OMR algorithm, IEEE standard 30-bus system is considered and tested. The results obtained with the proposed OMR algorithm are better than the other techniques in the literature.
Compact linear combination of composition operators on the weighted Bergman spaces
Authors: Kang Qijian , Wang Maofa
Published: September 2023

It is well-known that the research of linear combination of composition operators has become a topic of increasing interest. Recently, Choe, Koo and Wang proved that the compactness of combinations composition operators induced by the symbols satisfying the condition (CNC) implies that each difference is compact on the weighted Bergman space. Motivated by that work, in this paper, we discuss which difference is compact on the weighted Bergman space when the coefficients do not satisfy the condition (CNC).
We Do What We Are: Representation of the Self-Concept and Identity-Based Choice
Authors: Chen Stephanie Y , Urminsky Oleg , Yu Jiaqi
Published: September 2023

The current research proposes a novel approach to identity-based choice that focuses on consumers’ representations of the self-concept, as captured by the perceived cause–effect relationships among features of an individual consumer’s self-concept. More specifically, the studies reported here test the proposal that the causal centrality of an identity—the number of other features of a consumer’s self-concept that the consumer believes influenced or were influenced by the identity—underlies identity importance and is a determinant of identity-based consumer behaviors. Across seven studies, using both measured and manipulated causal centrality, the current research provides evidence for the role of causal centrality in identity-based choice. Among consumers who share an identity (belong to the same social category), those who believe that the identity is more causally central perceive the identity as more important and are more likely to engage in behaviors consistent with the norms of the social category.
JWST photometry of globular cluster populations in Abell 2744 at z = 0.3
Authors: Harris William E , Reina-Campos Marta
Published: September 2023

JWST imaging of the rich galaxy cluster Abell 2744 at z = 0.308 has been used by the UNCOVER team to construct mosaic images in the NIRCam filters. The exceptionally deep images in the (F115W, F150W, and F200W) bands reveal a large population of unresolved point-like sources across the field, the vast majority of which are globular clusters (GCs) or ultra-compact dwarfs. To the limits of our photometry, more than 10 000 such objects were measured, most of which are in the haloes of the five largest A2744 galaxies but which also include GCs around some satellite galaxies and throughout the intergalactic medium. The measured luminosity function covers almost 4 mag and follows a classic lognormal shape, though the GCLF turnover point still lies fainter than the photometric completeness limit. The colour index (F115W–F200W) in particular covers an intrinsic spread of 0.5 mag, clearly resolving the expected range of GC metallicities. The overall results are consistent with a large, normal GC population seen at a 3.5 Gyr earlier stage of dynamical evolution.
The effectiveness of intradiscal corticosteroid injection for the treatment of chronic discovertebral low back pain: a systematic review
Authors: Miller Scott , Caragea Marc , Carson Dan , McFarland Mary M , Teramoto Masaru , Cushman Daniel M , Cooper Amanda N , Burnham Taylor , McCormick Zachary L , Conger Aaron
Published: September 2023

Objective

Determine the effectiveness of intradiscal corticosteroid injection (IDCI) for the treatment of discovertebral low back pain.

Design

Systematic review.

Population

Adults with chronic low back pain attributed to disc or vertebral end plate pain, as evidenced by positive provocation discography or Modic 1 or 2 changes on magnetic resonance imaging.

Intervention

Fluoroscopically guided or computed tomography–guided IDCI.

Comparison

Sham/placebo procedure including intradiscal saline, anesthetic, discography alone, or other active treatment.

Outcomes

Reduction in chronic low back pain reported on a visual analog scale or numeric rating scale and reduction in disability reported by a validated scale such as the Oswestry Disability Index.

Methods

Four reviewers independently assessed articles published before January 31, 2023, in Medline, Embase, CENTRAL, and CINAHL. The quality of evidence was evaluated with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. The risk of bias in randomized trials was evaluated with the Cochrane Risk of Bias tool (version 2).

Results

Of the 7806 unique records screened, 6 randomized controlled trials featuring 603 total participants ultimately met the inclusion criteria. In multiple randomized controlled trials, IDCI was found to reduce pain and disability for 1–6 months in those with Modic 1 and 2 changes but not in those selected by provocation discography.

Conclusion

According to GRADE, there is low-quality evidence that IDCI reduces pain and disability for up to 6 months in individuals with chronic discovertebral low back pain as evidenced by Modic 1 and 2 changes but not in individuals selected by provocation discography.

Study registration

PROSPERO (CRD42021287421).
Placental DNA methylation analysis of selective fetal growth restriction in monochorionic twins reveals aberrant methylated CYP11A1 gene for fetal growth restriction
Authors: Shi Dayuan , Zhou Xinyao , Cai Luyao , Wei Xing , Zhang Luye , Sun Qianqian , Zhou Fenhe , Sun Luming
Published: September 2023

Fetal growth restriction (FGR) is associated with increased susceptibility to perinatal morbidity and mortality. Evidence suggests that epigenetic changes play critical roles in the regulation of fetal growth. We sought to present a comprehensive analysis of the associations between placental DNA methylation and selective fetal growth restriction (sFGR), which is a severe complication of monochorionic twin pregnancies, characterized by one fetus experiencing restricted growth. Genome‐wide methylation analysis was performed on 24 placental samples obtained from 12 monochorionic twins with sFGR (Cohort 1) using Illumina Infinium MethylationEPIC BeadChip. Integrative analysis of our EPIC data and two previous placental methylation studies of sFGR (a total of 30 placental samples from 15 sFGR twins) was used to identify convincing differential promoter methylation. Validation analysis was performed on the placentas from 15 sFGR twins (30 placental samples), 15 FGR singletons, and 14 control singletons (Cohort 2) using pyrosequencing, quantitative real‐time polymerase chain reaction, western blot, and immunohistochemistry (IHC). A globe shift toward hypomethylation was identified in the placentas of growth‐restricted fetuses compared with the placentas of normal fetuses in monochorionic twins, including 5625 hypomethylated CpGs and 452 hypermethylated CpGs, especially in the regions of CpG islands, gene‐body and promoters. The analysis of pathways revealed dysregulation primarily in steroid hormone biosynthesis, metabolism, cell adhesion, signaling transduction, and immune response. Integrative analysis revealed a differentially methylated promoter region in the CYP11A1 gene, encoding a rate‐limiting enzyme of steroidogenesis converting cholesterol to pregnenolone. The CYP11A1 gene was validated to have hypomethylation and higher mRNA expression in sFGR twins and FGR singletons. In conclusion, our findings suggested that the changes in placental DNA methylation pattern in sFGR may have functional implications for differentially methylated genes and regulatory regions. The study provides reliable evidence for identifying abnormally methylated CYP11A1 gene in the placenta of sFGR.
Upholding Our PROMISE: Underrepresented in Medicine Pediatric Residents' Perspectives on Interventions to Promote Belonging
Authors: Yemane Lahia , Kas-Osoka Oriaku , Burns Audrea , Blankenburg Rebecca , Prakash Laura Kester , Poitevien Patricia , Schwartz Alan , Lucas Candice Taylor , Marbin Jyothi
Published: September 2023

Purpose

Underrepresented in medicine (UIM) residents experience challenges during training that threaten their sense of belonging in medicine; therefore, residency programs should intentionally implement interventions to promote belonging. This study explored UIM pediatric residents' perspectives on current residency program measures designed to achieve this goal.

Method

The authors conducted a secondary qualitative analysis as part of a national cross-sectional study, PROmoting Med-ed Insight into Supportive Environments (PROMISE), which explored pediatric residents' experiences and perspectives during training in relation to their self-identities. A 23-item web-based survey was distributed through the Association of Pediatric Program Directors Longitudinal Educational Research Assessment Network from October 2020 to January 2021. Participants provided free-text responses to the question “What are current measures that promote a sense of belonging for the UIM community in your training program?” The authors used conventional content analysis to code and identify themes in responses from UIM participants.

Results

Of the 1,748 residents invited to participate, 931 (53%) residents from 29 programs completed the survey, with 167 (18%) identifying as UIM. Of the 167 UIM residents, 74 (44%) residents from 22 programs responded to the free-text question. The authors coded more than 140 unique free-text responses and identified 7 major themes: (1) critical mass of UIM residents; (2) focused recruitment of UIM residents; (3) social support, including opportunities to build community among UIM residents; (4) mentorship; (5) caring and responsive leadership; (6) education on health disparities, diversity, equity, inclusion, and antiracism; and (7) opportunities to serve, including giving back to the local community and near-peer mentorship of UIM premedical and medical students.

Conclusions

This is the first national study to describe UIM pediatric residents' perspectives on interventions that promote a sense of belonging. Programs should consider implementing these interventions to foster inclusion and belonging among UIM trainees.
Patient-Led Approaches to a Vaginal Birth After Cesarean Delivery Calculator
Authors: Rubashkin Nicholas , Asiodu Ifeyinwa , Vedam Saraswathi , Sufrin Carolyn , Adams Vincanne
Published: September 2023

OBJECTIVE:

To describe patient approaches to navigating their probability of a vaginal birth after cesarean (VBAC) within the context of prediction scores generated from the original Maternal-Fetal Medicine Units’ VBAC calculator, which incorporated race and ethnicity as one of six risk factors.

METHODS:

We invited a diverse group of participants with a history of prior cesarean delivery to participate in interviews and have their prenatal visits recorded. Using an open-ended iterative interview guide, we queried and observed these individuals' mode-of-birth decisions in the context of their VBAC calculator scores. We used a critical and feminist approach to analyze thematic data gleaned from interview and visit transcripts.

RESULTS:

Among the 31 participants who enrolled, their self-identified racial and ethnic categories included: Asian or South Asian (2); Black (4); Hispanic (12); Indigenous (1); White (8); and mixed-Black, -Hispanic, or -Asian background (4). Predicted VBAC success probabilities ranged from 12% to 95%. Participants completed 64 interviews, and 14 prenatal visits were recorded. We identified four themes that demonstrated a range of patient-led approaches to interpreting the probability generated by the VBAC calculator: 1) rejecting the role of race and ethnicity; 2) reframing failure, finding success; 3) factoring the physical experience of labor; and 4) modifying the probability for VBAC.

CONCLUSION:

Our findings demonstrate that a numeric probability for VBAC may not be highly valued or important to all patients, especially those who have strong intentions for VBAC. Black and Hispanic participants challenged the VBAC calculator's incorporation of race and ethnicity as a risk factor and resisted the implication it produced, especially that their bodies were less capable of achieving a vaginal birth. Our findings suggest that patient-led approaches to assessing and interpreting VBAC probability may be an untapped resource for achieving a more person-centered, equitable approach to counseling.