bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of F1–F2 Frequency Spacing on Spectral Integration in Combined Electric and Acoustic Stimulation
Authors: Jaisinghani Priyanka , Yoon Yang-Soo
Published: January 2025

Purpose:

The aim of this study was to measure the effects of frequency spacing (i.e., F2 minus F1) on spectral integration for vowel perception in simulated bilateral electric–acoustic stimulation (BiEAS), electric–acoustic stimulation (EAS), and bimodal hearing.

Method:

Twenty listeners with typical hearing participated in synthetic vowel recognition. Four vowels were used with varying frequency spacings (/ͻ/: 270 Hz, /ʊ/: 653 Hz, /æ/: 1040 Hz, and /I/: 1607 Hz). F1 was acoustically simulated with a band-pass filtering, while F2 was electrically simulated using an eight-channel sine wave vocoder with matched input and output frequency range. Vowel recognition was measured in five listening conditions: BiEAS (F1 and F2 in both ears), EAS (F1 and F2 in the left ear), bimodal (F1 and F2 in opposite ears), cochlear implant alone (F2 alone in the left ear), and hearing aid alone (F1 alone in the left ear).

Results:

In EAS, spectral integration was significantly better at a 270-Hz spacing, while in bimodal hearing, spectral integration was significantly poorer at a 1607-Hz frequency compared to other frequency spacings. BiEAS conditions offered the best spectral integration, regardless of frequency spacing. Vowel confusion remained consistent and below chance level across the first three listening conditions. Bimodal interference occurred for the /I/ vowel when the cochlear implant ear perceives the dominant cue and the hearing aid ear perceives the nondominant cue. The F2 place cue is transmitted significantly better than the F1 height cue in BiEAS, EAS, and bimodal conditions.

Conclusions:

EAS and bimodal hearing integrates narrower frequency ranges better than wider spacings. EAS hearing provided greater outcomes over bimodal hearing, suggesting that within-ear (EAS) integration is more effective than across-ear (bimodal) integration. Bimodal interference may be a factor for variability in bimodal performance. Cautious interpretation and further research with real EAS and bimodal users are suggested to validate and extend these findings.

Supplemental Material:

https://doi.org/10.23641/asha.28127249
Exploring the Feasibility of Self-Reported Cognitive Fatigue in Children With and Without Traumatic Brain Injury After Functional Experimental Tasks
Authors: Riccardi Jessica Salley , Underhill Brooke
Published: January 2025

Purpose:

The overall purpose of this study was to explore the feasibility of collecting subjective measures of cognitive fatigue in children with and without traumatic brain injury (TBI) before and after functional, experimental tasks.

Method:

Seven participants (i.e., two children with TBI and five children without TBI) completed the experimental tasks for this study. Demographics, injury information, and executive functioning were collected through an online, parent-reported survey. Self-reported ratings of cognitive fatigue were collected from children through an online survey and before and after four in-person experimental tasks, including two high-demand and two low-demand tasks.

Results:

All participants successfully completed the experimental tasks including self-rating cognitive fatigue before beginning the experiment and after each experimental task. While cognitive fatigue patterns were inconsistent across participants, changes in self-ratings were observed, demonstrating the feasibility of the tasks and measure for children with and without TBI.

Conclusion:

The findings from this preliminary study of a small sample support the feasibility of and continued research on self-ratings to better understand, assess, and manage cognitive fatigue after childhood TBI.
Collaborative optimization method for scalable prosumers’ participation in frequency regulation ancillary services
Authors: Pan Xi'an , Ai Xin , Gao Fei , Hu Junjie , Zhang Yingnan
Published: January 2025

As the demand for frequency regulation resources in power systems increases, collaborative optimization of flexible resources with rapid frequency regulation response capabilities, particularly by enabling scalable prosumers in local areas to participate in the frequency regulation ancillary service market, can effectively enhance safety, stability, and frequency regulation ability of power system. Therefore, this paper first establishes a collaborative optimization framework for scalable prosumers in frequency regulation and describes the operation model of prosumers. Considering the uncertainties that can impact prosumers' power decisions during frequency regulation, a scenario‐augmented dataset generation method based on a denoising diffusion probabilistic model is proposed to improve decision adaptability under extreme scenarios with insufficient regulation capabilities. Additionally, to enhance the scalability and applicability of the training method in scalable prosumer collaborative optimization scenarios, a multi‐agent attention proximal policy optimization algorithm combined with a global attention mechanism is introduced. The effectiveness of the proposed method in improving decision timeliness, operation benefits, scalability, and policy adaptability during scalable prosumers’ participation in frequency regulation ancillary services is validated using the IEEE standard node test system under various scales and scenarios.
Research on the registration of infrared and visible images based on phase consistency and edge extreme points
Authors: Li Jie , Zhou Rougang , Ruan Zhenchao , Chien Chou Jay Tsai , Zhu Junjie
Published: January 2025

Due to the significant differences in the imaging principles of infrared images and visible images, the feature points and descriptors between the two cannot be effectively matched directly by traditional feature extraction methods such as SIFT. To solve this problem, this study proposes a registration algorithm for infrared and visible images based on phase information and edge information. The algorithm extracts the feature points of the infrared image and the visible image through the principle of phase agreement and the edge binary map of the image and then calculates the descriptors of the gradient images of the infrared image and the visible image, and the descriptor calculation draws on some SIFT principles. Finally, the cosine similarity was used to match the feature points, and the improved random sample consensus algorithm was used to screen out the correct registration points. Experiments show that this method can effectively register between infrared and visible images and is also suitable for the registration of infrared and visible images with different rotation angles and similar structures.
Edge‐computing‐based operations for automated vehicles with different cooperation classes at stop‐controlled intersections
Authors: Soleimaniamiri Saeid , Yao Handong , Ghiasi Amir , Li Xiaopeng , Bujanović Pavle , Vadakpat Govindarajan , Lochrane Taylor W. P.
Published: January 2025

Cooperation classes have been defined by SAE International to differentiate the communication capabilities between vehicles and infrastructure. To advance understanding of the impact of cooperation classes on autonomous cooperative driving and optimize traffic operations, this article proposes an edge‐computing‐based operations framework for cooperative‐automated driving system (C‐ADS)‐equipped vehicles at a stop‐controlled intersection. First, a critical time points estimation component estimates a set of critical time points for each C‐ADS‐equipped vehicle. Second, a trajectory‐smoothing component is called at each C‐ADS‐equipped vehicle in a decentralized manner to control C‐ADS‐equipped vehicle trajectories based on the estimated critical time points and its cooperation behavior. Notably, this study represents a first‐time investigation of different cooperation classes for stop‐controlled intersections. Simulation results show that the proposed framework can reduce stop‐and‐go traffic, yielding significant improvements in mobility and energy efficiency, as the cooperation class increases. Results also demonstrate that the proposed framework is suitable for real‐time applications by distributing computational burden in different entities. Further, results verify that the proposed framework can handle varying speed errors without significant loss in performance.
Formulation and solution framework for real‐time railway traffic management with demand prediction
Authors: Pascariu Bianca , Flensburg Johan Victor , Pellegrini Paola , Azevedo Carlos M. Lima
Published: January 2025

Recent transport policies increasingly promote shifts towards rail travel aiming at a more sustainable transportation system. This shift is hampered by widespread unexpected perturbations in operations, resulting in perceived poor punctuality and reliability. When prevention of such perturbations is not feasible, traffic management must mitigate their effects, resolving arising conflicts to restore regular train operations and minimize delay. Current practice generally includes the assessment of railway performance in terms of train delays, but the quality of service to passengers is rarely explicitly accounted for. A railway traffic management framework is proposed that accounts for both passenger and train delays. To do so, a predictive optimization framework is proposed, integrating a demand prediction module, a passenger demand assignment module and a traffic management module. The first dynamically predicts future origin‐destination passenger flows using linear regression on real‐time observed smart card data. Then, the demand assignment module links predicted passengers to specific train paths, given a railway schedule. Finally, the traffic management module optimizes train scheduling and routing in real time, under the combined objective of minimizing train and passenger delays. The methodology is validated and benchmarked against equivalent passenger agnostic traffic management on a case study of the Copenhagen suburban railway network. The results show that it is possible to take into account passenger perspective in railway traffic management, without reducing the railway system efficiency compared to classic approaches.
Mechanical performance degradation modelling and prognosis method of high‐voltage circuit breakers considering censored data
Authors: Zhao Hongshan , Qian Yanan , Qu Yuehan
Published: January 2025

Due to the untimely deployment of sensors and the early retirement of high‐voltage circuit breakers, life‐cycle data is missing, leading to an inability to accurately predict the mechanical performance degradation trend. A new modelling and prediction method of mechanical performance degradation of high‐voltage circuit breakers considering censored data was proposed. Firstly, multiple imputation by chained equations was used to impute the missing values in the dataset of circuit breaker closing time, creating an interpolated dataset. Secondly, the Nadaraya–Watson kernel regression method was employed to smoothly estimate the interpolated dataset and eliminate data measurement errors. Then, the functional principal component analysis method was utilized to extract the common degradation trend component and deviation component to construct the degradation model. Finally, Bayesian inference was applied to dynamically update the degradation model parameters and predict the degradation trend of the high‐voltage circuit breaker. The results showed that the proposed method was capable of achieving better interpolation accuracy under the condition of different closing time censored data of high‐voltage circuit breakers. Moreover, as the degradation progressed, the dynamic prediction effect improved. The research can be used to provide an effective decision‐making basis for the operation and maintenance strategy of high‐voltage circuit breakers.
State-dependent signatures of jets and winds in the optical and infrared spectrum of the black hole transient GX 339–4
Authors: Ambrifi A. , Mata Sánchez D. , Muñoz-Darias T. , Sánchez-Sierras J. , Armas Padilla M. , Baglio M. C. , Casares J. , Corral-Santana J. M. , Cúneo V. A. , Fender R. P. , Ponti G. , Russell D. M. , Shidatsu M. , Steeghs D. , Torres M. A. P. , Ueda Y. , Vincentelli F.
Published: January 2025

GX 339–4 is one of the prototypical black hole X-ray transients, exhibiting recurrent outbursts that allow detailed studies of black hole accretion and ejection phenomena. In this work we present four epochs of optical and near-infrared spectroscopy obtained with X-shooter at the Very Large Telescope. The dataset includes two hard state spectra, collected during the 2013 and 2015 outbursts, and two soft state spectra observed during the 2021 outburst. Strong Balmer, Paschen, He I and He II emission lines are consistently observed in all spectra, while Brackett transitions and the Bowen blend are only prominent in the soft state. Although P-Cygni profiles are not identified, the presence of wind signatures, such as extended emission wings, flat-top and asymmetric red-skewed profiles, is consistently observed through most emission lines, suggesting the presence of wind-type ejecta. These features are particularly evident in the hard state, but they are also observed in the soft state, especially in the near-infrared. This strengthens the case for state-independent winds in black hole transients and increases the evidence for wind signatures in low-to-intermediate orbital inclination systems. We also study the spectral energy distribution, which provides evidence for the presence of synchrotron emission during the hard state. The jet significantly affects the near-infrared continuum, greatly diluting the emission features produced in the accretion flow. The simultaneous identification of both jet and wind signatures during the hard state reinforces the idea of a complex outflow scenario, in which different types of ejecta coexist.
Two decades of optical variability of Small Magellanic Cloud high-mass X-ray binaries
Authors: Treiber H. , Vasilopoulos G. , Bailyn C. D. , Haberl F. , Udalski A.
Published: January 2025

Aims. We present an analysis of the long-term optical/IR behavior of 111 high-mass X-ray binaries (HMXBs) in the Small Magellanic Cloud based on data from the OGLE collaboration.

Methods. Most systems exhibit variability on a range of time scales. This variability regulates the mass transfer to the compact object, while the compact object can, in turn, affect the donor star’s behavior. To better understand this complex interaction and the resulting X-ray properties in these systems, we define a new taxonomy for the observed super-orbital variability.

Results. This taxonomy connects to the color changes, orbital periods, and X-ray behavior of the sources. In most cases, these properties can be explained by differences between the flux of the disk around the Be star and the flux from the star itself. We also refine and present new potential orbital periods and sub-orbital variability in the sources.
The MeerKAT Fornax Survey
Authors: Loi F. , Serra P. , Murgia M. , Govoni F. , Vacca V. , Maccagni F. , Kleiner D. , Kamphuis P.
Published: January 2025

Using the Square Kilometre Array (SKA) mid precursor MeerKAT, we acquired broadband spectro-polarimetric data in the context of the MeerKAT Fornax Survey to study the Fornax cluster’s magnetic fields in detail by building the densest rotation measure (RM) grid to date. Here, we present the survey, the analysis, and a discussion of the RM grid properties. We analyzed a circular region centered on the Fornax cluster center with a radius of ∼1.4°; that is, ∼0.73Rvir. The mosaics have a resolution of 13″ and cover the frequencies between 900 MHz and 1.4 GHz, reaching an average noise of 16 μJy beam−1 in total intensity and 3 μJy beam−1 in the Q and U Stokes images. With these data, we detected 508 polarized sources over an area of ∼6.35 deg2 corresponding to a density of ∼80 polarized sources/deg2. This is the densest RM grid ever built. Of the polarized sources, five are cluster sources. Excluding the cluster sources, we built the Euclidean-normalized differential source counts in polarization and we went a factor of ten deeper than previous surveys. We tentatively detect for the first time an increment in the differential source counts at low polarized flux densities; that is, ∼9 μJy at 1.4 GHz. The average degree of polarization of about 3–4% suggests that the sub-μJansky population is not dominated by star-forming galaxies, typically showing a degree of polarization lower than 1%. The majority of the polarized sources are Faraday simple; in other words, their polarization plane rotates linearly with the wavelength squared. The RM shows the typical decrement going from the center to the outskirts of the Fornax cluster. However, interesting features are observed both in the RM grid and in the RM radial profiles across different directions. A combination of the cluster physics and large-scale structure filaments surrounding the Fornax cluster could explain the RM characteristics.
Discovery of polarized X-ray emission from the accreting millisecond pulsar SRGA J144459.2–604207
Authors: Papitto Alessandro , Di Marco Alessandro , Poutanen Juri , Salmi Tuomo , Illiano Giulia , La Monaca Fabio , Ambrosino Filippo , Bobrikova Anna , Cristina Baglio Maria , Ballocco Caterina , Burderi Luciano , Campana Sergio , Coti Zelati Francesco , Di Salvo Tiziana , La Placa Riccardo , Loktev Vladislav , Long Sinan , Malacaria Christian , Miraval Zanon Arianna , Ng Mason , Pilia Maura , Sanna Andrea , Stella Luigi , Strohmayer Tod , Zane Silvia
Published: January 2025

We report the discovery of polarized X-ray emission from an accreting millisecond pulsar. During a 10-day-long coverage of the February 2024 outburst of SRGA J144459.2−604207, the Imaging X-ray Polarimetry Explorer (IXPE) detected an average polarization degree of the 2–8 keV emission of 2.3%±0.4% at an angle of 59° ±6° (east of north; the uncertainties quoted are at the 1σ confidence level). The polarized signal shows a significant energy dependence with a degree of 4.0%±0.5% between 3 and 6 keV and < 1.5% (90% c.l.) in the 2–3 keV range. We used NICER, XMM–Newton, and NuSTAR observations to obtain an accurate pulse-timing solution and to perform a phase-resolved polarimetric analysis of IXPE data. We did not detect any significant variability in the Stokes parameters Q and U with the spin and orbital phases. We used the relativistic rotating-vector model to show that a moderately fan-beam emission from two point-like spots at low magnetic obliquity (≃10°) is compatible with the observed pulse profile and polarization properties. IXPE also detected 52 type I X-ray bursts whose recurrence time Δtrec increased from 2 to 8 h as a function of the observed count rate C as Δtrec ∝ C−0.8. We stacked the emission observed during all the bursts and obtained an upper limit on the polarization degree of 8.5% (90% c.l.).
A study of the frequency and characteristics of stellar companions and Jupiter-like planets in nearby open clusters
Authors: Gratton R. , Bonavita M. , Mesa D. , Desidera S. , Zurlo A. , Marino S. , D’Orazi V. , Rigliaco E. , Nascimbeni V. , Barbato D. , Columba G. , Squicciarini V.
Published: January 2025

Context. Observations of companions of solar-type stars in nearby young moving groups (NYMGs) show that they split into two groups: stellar and brown dwarf companions (mass ratio q > 0.05) and Jupiter-like (JL) planets (q < 0.02). The frequency of JL planets in NYMGs appears to be higher than that obtained from radial velocity (RV) surveys.

Aims. We extended the search for companions to three nearby clusters of intermediate age: Hyades, Coma Berenices, and Ursa Major. They are older and formed in more massive events than the NYMGs.

Methods. The sample of host stars is complete for the core of the clusters, while we considered only a fraction of the tidal tails. We used the same methods considered for the members of NYMGs.

Results. We obtained a fairly complete sample of stellar companions and detected six massive JL planets. We found a lower frequency of equal-mass companions than in the NYMGs; this might be related to how binaries form in these environments. We also observed a concentration of stellar binaries in the cores of Ursa Major and Coma Berenices; we attribute this to the selective loss of low-mass systems. The observed scarcity of wide companions in Hyades can be due to the destruction of binaries in close encounters. The frequency of JL planets is lower than in the NYMGs but similar to that obtained from RV surveys. This extends the correlation with age and mass previously found for NYMGs.

Conclusions. Results of this study alone do not indicate whether age or mass are the factors driving the observed correlation. A comparison of the frequencies of free-floating planets from microlenses and in young associations favours mass as the main driving parameter. Once the initial cluster mass function is considered, the frequency of JL planets in NYMGs is consistent with the results obtained using RVs.
Continuation of an optical spectroscopic campaign of Fermi blazar candidates with TNG: Discovery of a new changing-look blazar
Authors: Álvarez Crespo N. , Domínguez A. , Paliya V. S. , Chamorro Cazorla M. , Sánchez Blázquez P. , Gil de Paz A.
Published: January 2025

Context. Blazars are a distinct subclass of active galactic nuclei (AGN), known for their fast variability, high polarization, and intense emission across the electromagnetic spectrum, from radio waves to gamma rays. Gamma-ray blazar candidates of uncertain type (BCU) are an ongoing challenge in gamma-ray astronomy due to difficulties in classification and redshift determination.

Aims. This study continues an optical spectroscopic campaign aimed at identifying the characteristics of BCUs to improve classification and redshift estimates, particularly focusing on low-synchrotron-peak sources.

Methods. We conducted a detailed analysis of optical spectroscopic data for a sample of 21 low-synchrotron-peak BCUs plus one bl lac with contradictory results in the literature, using the 3.58-m Telescopio Nazionale Galileo (TNG, La Palma, Spain).

Results. Our analysis identifies 14 out of the 21 BCUs as flat-spectrum radio quasars (FSRQs), demonstrating the effectiveness of our selection criteria. Notably, four FSRQs have redshifts exceeding 1, including 4FGL J2000.0+4214 at z = 2.04. Six sources are classified as bl lacs, with one of them, 4FGL J0746.5−0719, showing a featureless spectrum in this work despite previously exhibiting strong lines, suggesting it may be a changing-look blazar. One source remains classified as a BCU due to a noisy spectrum. Additionally, we observed a bl lac object, 4FGL J1054.5+2211, due to inconsistent redshift estimates in the literature, but we could not confirm any redshift due to its featureless spectrum. Our findings provide insights into the classification and redshift estimation of blazar candidates, emphasizing the need for continued spectroscopic monitoring.
The puzzle of isolated and quenched dwarf galaxies in cosmic voids
Authors: Bidaran Bahar , Pérez Isabel , Sánchez-Menguiano Laura , Argudo-Fernández María , Ferré-Mateu Anna , Navarro Julio F. , Peletier Reynier F. , Ruiz-Lara Tomás , van de Ven Glenn , Verley Simon , Zurita Almudena , Duarte Puertas Salvador , Falcón-Barroso Jesús , Sánchez-Blázquez Patricia , Jiménez Andoni
Published: January 2025

We report, for the first time, the detection of a sample of quenched and isolated dwarf galaxies (with 8.9 < log(M⋆/M⊙) < 9.5) in the least dense regions of the cosmic web, including voids, filaments, and walls. These dwarfs have no neighboring galaxy within 1.0 Mpc in projected distance. Based on the full spectral fitting of their central spectra using Sloan Digital Sky Survey data, these galaxies are gas-deprived, while also exhibiting a stellar mass assembly very similar to dwarfs in the central regions of galaxy clusters. Furthermore, they have experienced no significant star formation in the past 2 Gyr. Additionally, analyses of r-band images from the Dark Energy Camera Legacy Survey have shown that these dwarf galaxies host a central nuclear star cluster (NSC). Detecting quenched, isolated dwarf galaxies in cosmic voids indicates that environmental factors are not the sole drivers of their quenching. Internal mechanisms, such as feedback from in situ star formation, which also contribute to the NSC formation, along with black holes or variations in the conditions around their formation, offer potential explanations for star formation suppression in these galaxies. These findings highlight the need for a significant revision in our understanding of baryonic physics, particularly concerning the formation and evolution of low-mass galaxies.
Impact of the observation frequency coverage on the significance of a gravitational wave background detection in pulsar timing array data
Authors: Ferranti I. , Falxa M. , Sesana A. , Chalumeau A. , Porayko N. , Shaifullah G. , Cognard I. , Guillemot L. , Kramer M. , Liu K. , Theureau G.
Published: January 2025

Pulsar timing srray (PTA) collaborations gather high-precision timing measurements of pulsars, with the aim of detecting gravitational wave (GW) signals. A major challenge lies in the identification and characterisation of the different sources of noise that may hamper their sensitivity to GWs. The presence of time-correlated noise that resembles the target signal might give rise to degeneracies that can directly impact the detection statistics. In this work, we focus on the covariance that exists between a ‘chromatic’ dispersion measure (DM) noise and an ‘achromatic’ stochastic gravitational wave background (GWB). The term ‘chromatic’ associated with the DM noise means that its amplitude depends on the frequency of the incoming pulsar photons measured by the radio telescopes. Multi-frequency coverage is then required to accurately characterise its chromatic features and when the coverage of incoming frequency is poor, it becomes impossible to disentangle chromatic and achromatic noise contributions. In this paper, we explore this situation by injecting realistic GWB into 100 realisations of two mock versions of the second data release (DR2) of the European PTA (EPTA), characterised by different types of frequency coverage. The first dataset is a faithful copy of DR2, in which the first half of the data is dominated by only one frequency channel for the observations; the second one is identical, except for a more homogeneous frequency coverage across the full dataset. We show that for 91% of the injections, a better frequency coverage leads to an improved statistical significance (≈1.3 dex higher log Bayes factor on average) of the GWB and a better characterisation of its properties. We propose a metric to quantify the degeneracy between DM and GWB parameters. We show that it is correlated with a loss of significance for the recovered GWB, as well as with an increase in the GWB bias towards a higher and flatter spectral shape. In the second part of the paper, this correlation between the loss of GWB significance, the degeneracy between the DM and GWB parameters, and the frequency coverage is further investigated using an analytical toy model.
Conditions for radiative zones in the molecular hydrogen envelope of Jupiter and Saturn: The role of alkali metals
Authors: Siebenaler L. , Miguel Y. , de Regt S. , Guillot T.
Published: January 2025

Context. Interior models of gas giants in the Solar System traditionally assume a fully convective molecular hydrogen envelope. However, recent observations from the Juno mission suggest a possible depletion of alkali metals in Jupiter’s molecular hydrogen envelope, indicating that a stable radiative layer could exist at the kilobar level. Recent studies propose that deep stable layers help reconcile various Jupiter observations, including its atmospheric water and CO abundances and the depth of its zonal winds. However, opacity tables used to infer stable layers are often outdated and incomplete, leaving the precise molecular hydrogen envelope composition required for a deep radiative zone uncertain.

Aims. In this paper, we determine atmospheric compositions that can lead to the formation of a radiative zone at the kilobar level in Jupiter and Saturn today.

Methods. We computed radiative opacity tables covering pressures up to 105 bar, including the most abundant molecules present in the gas giants of the Solar System, as well as contributions from free electrons, metal hydrides, oxides, and atomic species, using the most up-to-date line lists published in the literature. These tables were used to calculate Rosseland-mean opacities for the molecular hydrogen envelopes of Jupiter and Saturn, which were then compared to the critical mean opacity required to maintain convection.

Results. We find that the presence of a radiative zone is controlled by the existence of K, Na, and NaH in the atmosphere of Jupiter and Saturn. For Jupiter, the elemental abundance of K and Na must be less than ∼10−3 times solar to form a radiative zone. In contrast, for Saturn, the required abundance for K and Na is below ∼10−4 times solar.
Unveiling the binary nature of NGC 2323
Authors: Qin Songmei , Zhong Jing , Tang Tong , Jiang Yueyue , Wang Long , Wu Kai , Anders Friedrich , Balaguer-Núñez Lola , Liu Guimei , Li Chunyan , Hou Jinliang , Chen Li
Published: January 2025

Context. As a well-known open cluster, NGC 2323 (also called M50) has been widely investigated for over a hundred years and has always been considered a classical single cluster.

Aims. We studied the binary structure nature of NGC 2323 with Gaia Data Release 3 (DR3).

Methods. We discovered the binary structure of NGC 2323 by the HDBSCAN algorithm based on the astrometric and photometric data from Gaia DR3. Then we employed the PETAR N-body code to investigate its binary structure origin.

Results. We found that NGC 2323 consists of two distinct subclusters (NGC 2323-a and NGC 2323-b) that are still gravitationally bound. They have very close positions (three-dimensional Δpos = 12.3 pc, σΔpos = 3.4 pc) and similar tangential velocities (two-dimensional ΔV = 2.2 km s−1, σΔV = 0.02 km s−1). The best isochrone fitting ages of the two clusters are the same (158 Myr), further proving their possibly common origin. The numerical N-body simulation suggests that the less massive cluster is unlikely to be the cluster tidal tails created by the differential rotation of the Milky Way.
VLTI/GRAVITY enables the determination of the first dynamical masses of a classical Be + stripped and bloated pre-subdwarf binary
Authors: Klement R. , Rivinius Th. , Baade D. , Mérand A. , Bodensteiner J. , Frost A. J. , Sana H. , Shenar T. , Gies D. R. , Hadrava P.
Published: January 2025

Context. HR 6819 is the first post-mass transfer binary system composed of a classical Be star and a bloated pre-subdwarf stripped star directly confirmed by interferometry. While the Be star is already spun up to near-critical rotation and possesses a self-ejected viscous Keplerian disk, the stripped star is found in a short-lived evolutionary stage, in which it retains the spectral appearance of a B-type main-sequence star while contracting into a faint subdwarf OB-type star.

Aims. In order to understand the evolution of intermediate-mass interacting binaries, the fundamental parameters of cornerstone objects such as HR 6819 need to be known. We aim to obtain orbital parameters and model-independent dynamical masses of this binary system to quantitatively characterize this rarely observed evolutionary stage.

Methods. We analyzed a time series of 12 interferometric near-IR K-band observations from VLTI/GRAVITY with the help of the geometrical model-fitting tool PMOIRED. We included recently published radial velocities based on FEROS high-resolution spectroscopy for the binary orbital solution.

Results. With the GRAVITY data, we obtained the astrometric orbit, relative fluxes of the components, and parameters of the circumstellar disk of the Be star; we also detected helium line signatures from the stripped star. Using the published radial velocities enabled us to obtain the dynamical masses of the components as well as the dynamical parallax. The Be star is the slightly brighter component in the K band and is almost 16 times as massive as the bloated stripped star, with the individual dynamical masses being 4.24 ± 0.31 M⊙ for the Be star and 0.270 ± 0.056 M⊙ for the stripped star. The orbit is slightly eccentric, with e = 0.0289 ± 0.0058, and the semimajor axis of the orbit is 0.3800 ± 0.0093 AU. The distance derived from the orbital solution is 296.0 ± 8.0 pc, significantly lower than the distance from Gaia DR3, which is overestimated by ∼24% due to the orbital motion.

Conclusions. The newly obtained fundamental parameters provide an important anchor for evolutionary models of interacting binaries and for the physics of mass transfer. The low mass of the bloated star means that it may become completely undetectable once it settles into a faint subdwarf, which implies that many more Be stars may have low-mass companions despite appearing single.
Green chemistry and catalysis: An emerging sustainable approach in synthetic chemistry
Authors: Kaur Amandeep , Goyal Anju , Kumari Sapna , Garg Madhukar , Sharma Shiwali , Akram Muhammad , Laila Umme , Talha Khalil Muhammad , Kaur Paranjeet , Kumar Sahu Sanjeev
Published: January 2025

This tutorial review summarizes the basic new concepts of green chemistry in relation to education and pharmaceutical industries. The origin and history of Green analytical chemistry is described in detail. Basic twelve principles are well summarized with suitable examples of each principle such as oxidation of alcohol, enzymatic reactions, and non-covalent derivatization. This article also covers the concept of E-factor for waste minimization, detailed various solvent selection guidelines and tools for betterment of synthetic pathways at laboratory and industrial level. The efficiency of green chemistry in organic synthesis for greenness of traditional organic synthesis methods are discussed. Nowadays, there is a constant need to add catalysts for chemical synthesis to minimize or downsize the risks correspondent with chemical manufacture. Catalyst helps to enhance air quality by reducing harmful gas emissions such as NOx. It cuts down on the use of VOCs (volatile organic compounds). It developed an alternative catalytic method which substitutes the usage of chlorine-based intermediates in chemical synthesis and processes. Biocatalysts is a term used to describe compounds that aid in the stimulation of biological reactions. In the fine chemical industry, cleaner biocatalytic alternatives are replacing traditional chemical operations.
Assessment of Real-Time Natural Language Processing for Improving Diagnostic Specificity: A Prospective, Crossover Exploratory Study
Authors: Jindal Atin , Andrea Sarah B. , O'Brien Jill , Gillerman Richard
Published: January 2025

Background
Reliable, precise, timely, and clear documentation of diagnoses is difficult. Poor specificity or the absence of diagnostic documentation can lead to decreased revenue and increased payor denials, audits, and queries to providers. Nuance’s Dragon Medical Advisor (DMA) is a computer-assisted physician documentation (CAPD) product. Natural language processing is used to present real-time advice on diagnostic specificity during documentation.
Objectives
This study assessed the feasibility, acceptability, and preliminary efficacy of real-time CAPD in improving diagnostic specificity and in turn reducing clinical documentation improvement burden.
Methods
This prospective, crossover trial recruited 18 hospitalists employed by Lifespan Health System and assigned them randomly to two groups. Each group first completed documentation using either traditional clinical documentation improvement (CDI) methods or CDI + DMA real-time advice for eight weeks and then crossed over. Metrics from Epic’s EMR and Nuance administrative tools as well as anonymous surveys and one-on-one interviews were collected and analyzed.
Results
Hospitalists had 29% fewer standard CDI queries using DMA with CDI (IRR: 0.71; 95% CI: 0.37,1.39). Self-reported ability to predict clarification requests improved by 1 point on average (1.00; 95% CI: 0.32,1.67) on the Likert scale. This benefit was kept even after DMA was stopped and the group reverted back to CDI only. Qualitative survey reports indicated overall ease of use and educational benefits. Additional work needs to be done to determine if there is significant increase in note-writing time or reimbursement.
Conclusions
Hospitalists using DMA spent less time responding to In-basket queries. There was a strong educational opportunity, and the tool was easy to use. DMA offers promise for improving diagnostic specification while minimally impacting provider workflow.
Fulminant Heterotopic Ossification following COVID-19 associated Systemic Inflammatory Response Syndrome: Manifestations in Radiology, Nuclear Medicine, and Clinical Application
Authors: Kalbi Deepak P. , Zamora Edgar , Hari Adithya , Chun Kwang J.
Published: January 2025

Heterotopic ossification (HO) is an unclear etiological trigger that results in diverse extra-skeletal bone formation in muscles and soft tissues. This often results in morbidity and reduced quality of life with pain, contractures, and mobility impairment. We present two patients with HO with a history of severe COVID-19 infection requiring 1-month-long mechanical ventilation. The first patient was found to have progressive stiffening of the right knee and left elbow, with clear demonstration of radiographic findings and active dystrophic calcification by nuclear medicine three-phase bone scan. This report might help aid earlier recognition of symptoms for an effective prevention of this debilitating disease. The other patient was also being treated with severe COVID-19, requiring intensive care unit stay with mechanical ventilation demonstrating progressive development of HO on the follow-up computed tomography (CT) images. While abdominal CT studies were obtained for this patient to evaluate the focal sites for infection, the patient was too ill and unable to undergo a bone scan study.
Turning Your Presentations/Posters to Publications
Authors: Prasad Shweta , Garg Ajay , Saini Jitender
Published: January 2025

A scientific manuscript or paper is invariably the ultimate goal of most scientific endeavors and in a majority of cases, the final manuscript often begins as an abstract submitted to a conference to be presented as either a poster or an oral presentation. It is practically possible for authors to use a conference presentation as a basic template to expand and write a complete manuscript. However, it is imperative for authors to acknowledge the limitations of these abstracts and make attempts to improve the quality of work before embarking on writing a full-length manuscript. This article aims to provide a structured approach to how to write a paper primarily based on a conference abstract, along with examples and limitations.
Random walks with stochastic resetting in complex networks: A discrete-time approach
Authors: Michelitsch Thomas M. , D’Onofrio Giuseppe , Polito Federico , Riascos Alejandro P.
Published: January 2025

We consider a discrete-time Markovian random walk with resets on a connected undirected network. The resets, in which the walker is relocated to randomly chosen nodes, are governed by an independent discrete-time renewal process. Some nodes of the network are target nodes, and we focus on the statistics of first hitting of these nodes. In the non-Markov case of the renewal process, we consider both light- and fat-tailed inter-reset distributions. We derive the propagator matrix in terms of discrete backward recurrence time probability density functions, and in the light-tailed case, we show the existence of a non-equilibrium steady state. In order to tackle the non-Markov scenario, we derive a defective propagator matrix, which describes an auxiliary walk characterized by killing the walker as soon as it hits target nodes. This propagator provides the information on the mean first passage statistics to the target nodes. We establish sufficient conditions for ergodicity of the walk under resetting. Furthermore, we discuss a generic resetting mechanism for which the walk is non-ergodic. Finally, we analyze inter-reset time distributions with infinite mean where we focus on the Sibuya case. We apply these results to study the mean first passage times for Markovian and non-Markovian (Sibuya) renewal resetting protocols in realizations of Watts–Strogatz and Barabási–Albert random graphs. We show nontrivial behavior of the dependence of the mean first passage time on the proportions of the relocation nodes, target nodes, and of the resetting rates. It turns out that, in the large-world case of the Watts–Strogatz graph, the efficiency of a random searcher particularly benefits from the presence of resets.
Research on the numerical simulation of dynamic explosion shock wave propagation characteristics between floors
Authors: Wu Ke , Chen Bo , Li Hao , Zhang Yunfeng , Zhang Damin , Wu Yixuan , Sui Yaguang
Published: January 2025

This study addresses the assessment of dynamic explosive shock wave loads in building damage evaluation. Utilizing numerical simulation methods, we investigated the propagation process of shock waves between building floors, capturing the evolution of their wavefronts. We particularly focused on discussing the variation patterns of pressure peaks caused by vertical shock wave reflections. Computational analysis indicates that under static conditions, inter-floor explosive shock wave overpressure peaks are significantly stronger than those from free-field explosions. Specifically, within a distance range of 2–3 m/kg1/3, the overpressure peak from inter-floor explosions is approximately three times greater than that from free-field explosions. In scenarios involving an equivalent charge of 400 kg and initial velocities ranging up to 1200 m/s, it was observed that shock waves propagate as partially spherical wavefronts within a distance of 15 m between floors; beyond this range, they evolve into nearly planar wavefront propagation. Within this 15 m range, constraints imposed by floor slabs lead to non-uniform and continuously varying vertical pressure distributions. After two reflections, the vertical pressure distribution approaches uniformity. For cylindrical charges, the characteristics of vertical distribution changes in shock waves can be categorized into four stages (while spherical charges correspond to three characteristic stages). The intensity of these variations is primarily influenced by the initial velocity of the explosion source and shows insensitivity toward both the length–diameter ratio and equivalence weight of the charge. Moreover, a model capable of assessing this pressure non-uniformity feature has been established in this paper, which can estimate the pressure distribution characteristics under different initial velocity circumstances rather rapidly and accurately.
Soliton and rogue wave excitations in the Chen–Lee–Liu derivative nonlinear Schrödinger equation with two complex PT-symmetric potentials
Authors: Liu Ping , Chen Yong , Chai Xuedong
Published: January 2025

We demonstrate that fundamental nonlinear localized modes can exist in the Chen–Lee–Liu equation modified by several parity-time (PT) symmetric complex potentials. The explicit formula of analytical solitons is derived from the physically interesting Scarf-II potential, and families of spatial solitons in internal modes are numerically captured under the optical lattice potential. By the spectral analysis of linear stability, we observe that these bright solitons can remain stable across a broad scope of potential parameters, despite the breaking of the corresponding linear PT-symmetric phases. When these bright spatial solitons interact with external incident waves, they can always maintain their original shape, while the external incident wave may remain unchanged or may generate a reflected wave after the interaction. Then, the adiabatic switching of potential parameters is carried out in a way that allows these bright solitons to be excited from one unstable bound state to another alternative stable bound state. Many other intriguing properties associated with these nonlinear localized modes including the lateral power flow are further analyzed meticulously. Various high-order rogue waves induced by modulation instability in these PT-symmetric systems are generated too. These results may be useful to construct novel optical soliton communication schemes or design related optical materials.
Exploration of Bogdanov–Takens and Hopf bifurcation through coupling of nonlinear recovery with multiple reinfections of COVID-19
Authors: Devi Arpita , Kumar Gupta Praveen
Published: January 2025

This study introduces a five-compartment model to account for the impacts of vaccination-induced recovery and nonlinear treatment rates in settings with limited hospital capacity. To reflect real-world scenarios, the model incorporates multiple reinfections in both vaccinated and recovered groups. It reveals a range of dynamics, including a disease-free equilibrium and up to six endemic equilibria. Notably, the model demonstrates that COVID-19 can persist even when the basic reproduction number is less than one, due to backward bifurcation, which conditions the global stability of the disease-free equilibrium. Various bifurcations are analyzed, including saddle-node, Bogdanov–Takens of codimension-2, and Hopf bifurcation of codimension-1. As transmission rates increase, unstable oscillations stabilize, with the Hopf bifurcation becoming supercritical. The model also highlights forward hysteresis, driven by the multistability of endemic equilibria. Key factors influencing the disease’s local endemic behavior, such as effective transmission rates and reinfection rates among vaccinated and recovered individuals, are emphasized. Numerical simulations validate the model and underscore its practical relevance.
Hostile environments, terminal habitat, and tomb trees: the impact of systemic failures to survey for mature-forest dependent species in the State forests of New South Wales
Authors: Wardell-Johnson Grant W. , Robinson Todd P.
Published: January 2025

Context The Coastal Integrated Forestry Approval (CIFOA) areas of New South Wales (NSW), Australia include most populations of at least two threatened species of glider Petaurus australis australis (Yellow-bellied Glider [south-eastern]) and Petauroides volans (Greater Glider [Southern and Central]). The NSW Environmental Protection Authority (EPA) administers protocols to conserve gliders within forest compartments intensively managed for timber production by Forests Corporation NSW (FCNSW). These protocols include pre-logging surveys and retention of hollow-bearing trees (HBTs), den trees, and associated buffers. Citizen scientists have ground-truthed these protocols in some compartments. Aims We assessed the effectiveness of surveys by FCNSW and associated outcomes in the context of planned logging operations. Methods We used the publicly available EPA Native Forestry map viewer data for this analysis. Key results Although gliders have been detected and abundant HBTs retained in 10 State forests, no den trees were identified by FCNSW in any ‘active’ compartment (as at December 2023). Thus, isolated HBTs or tomb trees were retained without associated buffers. Several phases of EPA protocols have not improved the outcomes for glider conservation within logged compartments, even when complied with by FCNSW. Conclusions Based on the FCNSW data and on citizen science, surveys implemented by FCNSW under CIFOA protocols result in poor outcomes for gliders and other mature forest dependent species. Wholesale changes in process are likely required for effective conservation. Implications New approaches in monitoring and research commitment, administration, and oversight are likely required to halt the increasingly rapid decline of threatened gliders, as well as local forest communities in the State forests of NSW.