bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance Evaluation of a Visual Defects Detection System for Railways Monitoring
Authors: Radosavljevic Saša , Rivero Alain , Rodríguez Flórez Sergio , El Ouardi Abdelhafid , Michel Pauline , Bouamama Belkacem O. , Vanheeghe Philippe
Published: December 2024

SNCF Réseau introduces a novel multi-modal embedded monitoring system, addressing challenges in railway infrastructure maintenance. The design incorporates visual, inertial, and sound sensors, enhancing adaptability, improving overall detection precision, and could reduce operational costs. This study addresses visual defects detection that can be integrated in a multi-modal monitoring system. The paper details the system’s architecture, synchronisation methods, and decision fusion process to improve the precision of limited mono-modal systems. A deep-learning visual based railway defects inspection was explored. Results show that small CNN (Yolov8 nano) can achieve similar (Yolov8 XL) high precision (mAP@0.5 ≥ 0.89) for a small number of objects (9) while improving implementation capability on embedded systems.
Cannabis und Nikotin in deutschen Musikvideos
Authors: Hanewinkel Reiner , Neumann Clemens , Morgenstern Matthis
Published: December 2024

Hintergrund Das Rauchen von Tabak und Cannabis ist in Deutschland weit verbreitet. Kinder und Jugendliche vom Einstieg in den Konsum dieser Rauchprodukte abzuhalten, ist ein wichtiges Ziel der Prävention. Es wurde untersucht, wie häufig Cannabis- und Nikotinkonsum in deutschsprachigen Musikvideos vorkommen und dadurch Werbung fürs Rauchen gemacht wird.

Methode Die Stichprobe umfasste die Grundgesamtheit aller deutschsprachigen Musikvideos, die im Jahr 2023 in den YouTube-Top-100-Charts gelistet wurden. Sie beinhaltete 600 Musikvideos. Durch ein Kodierungsschema wurden die Musikvideos in die Kategorien „rauchfrei“ und „nicht rauchfrei“ eingeteilt und das Darstellen oder Erwähnen des Konsums ausgezählt.

Ergebnisse 54,7% (n=328) der Videos beinhaltete mindestens eine Darstellung oder Erwähnung des Konsums von Cannabis oder Tabak. In 31,7% der Videos (n=190) ging es ausschließlich um Tabakkonsum, in 12,5% der Videos (n=75) ausschließlich um Cannabiskonsum, in 10,5% (n=63) um beides. Während in 67,0% der Videos aus dem Genre „Deutschrap“ Tabak- oder Cannabiskonsum gezeigt oder erwähnt wurde, waren es bei den anderen Genres im Mittel 20,6% (OR=7,83; p<0,001). Bei Betrachtung des Cannabiskonsums allein war der Unterschied zwischen den Genres noch deutlicher. So lag der Anteil an Videos, in denen Cannabis gezeigt oder erwähnt wurde, im Genre „Deutschrap“ bei 29,7%, in den übrigen Genres bei 4,4% (OR=9,27; p<0,001). Die 328 Videos, in denen Tabak- oder Cannabiskonsum gezeigt wurde, kamen auf 3,2 Mrd. Klicks (64,5% der Klicks). Daraus ergibt sich, dass diese 328 Videos insgesamt 9,7 Bio. Impressionen generierten. Davon entfielen 5,8 Bio. Impressionen auf Nikotinkonsum und 3,9 Bio. Impressionen auf Cannabiskonsum.

Diskussion Weitgehend unreguliert werden Kinder und Jugendliche durch Musikvideos einer Vielzahl von Nikotin- und Cannabiskonsumszenen ausgesetzt.
Association between CACNA1A and ATP1A2 Variants are Responsible for Severe Neurodevelopmental Disorder
Authors: Mouraux Charlotte , Alkan Serpil , Caberg Jean-Hubert , Depierreux Frédérique
Published: December 2024

ATP1A2 and CACNA1A genes encode proteins forming transmembrane channels, Na+/K+/ATPase transporter, and voltage-gated calcium channels, respectively. Pathogenic variants in these genes are associated with hemiplegic migraines, movement disorders, and developmental and epileptic encephalopathy.

We report a child presenting epileptic encephalopathy with cognitive and behavioral troubles. He carries a likely pathogenic variant in the ATP1A2 gene, inherited from his mother who presents hemiplegic migraines, and a variant of uncertain significance in the CACNA1A gene, inherited from his asymptomatic father and also found in his brother, who presents a milder neurodevelopmental disorder (NDD). No other significant copy number or single nucleotide variations were identified after an in-depth genetic study including whole exome sequencing, array comparative genomic hybridization, and screening for Fragile X and Prader–Willi/Angelman syndromes.

We illustrate the synergetic impact of ATP1A2 and CACNA1A genes in NDDs.
Intra-Articular Adductor Canal Block Has Equivalent Analgesic Effect to Traditional Ultrasound-Guided Adductor Canal Block after Total Knee Arthroplasty: A Prospective Randomized Controlled Trial
Authors: Huang Deyong , Zhang Dazhi , Jiang Yi , Yi Jun , Sun Ke , Shao Hongyi
Published: December 2024

An adductor canal block (ACB) is widely accepted as a regional nerve block for pain management following total knee arthroplasty (TKA). However, no consensus exists concerning whether the analgesic effect is greater when joint surgeons perform intra-articular ACBs (IA-ACBs) or when anesthesiologists perform ultrasound-guided ACBs (UG-ACBs). We hypothesized that IA-ACBs performed by joint surgeons and UG-ACBs performed by anesthesiologists based on periarticular injections (PAIs) would yield equivalent analgesic effects. This prospective randomized controlled trial included 61 patients who underwent IA-ACBs and 56 patients who received UG-ACB with additional PAI for post-TKA pain management. The primary outcome was postoperative pain assessed using numeric rating scale scores at rest and during exercise. Secondary outcomes included opioid consumption and functional recovery. We also investigated local and systemic adverse events, including nausea, vomiting, and wound complications. Both groups of patients experienced comparable analgesic effects for both IA-ACB and UG-ACB pain management; however, those who received IA-ACBs were prescribed more opioid equivalents than those in the UG-ACB group on postoperative day 1 (p = 0.048). No differences between the groups were observed regarding local or systemic adverse events. IA-ACBs performed by joint surgeons provided equivalent analgesic effects to UG-ACBs performed by anesthesiologists. However, IA-ACBs may lead to a higher postoperative requirement for opioid analgesics.
Photocatalytic Defluorinative Borylation of α-(Trifluoromethyl)styrenes
Authors: Stavagna Chiara , Buettner Cornelia S.
Published: December 2024

The defluorinative radical borylation of α-(trifluoromethyl)styrenes is a novel access to diverse difluoroalkene-aminoboranes in good yields. Using the boryl radical precursor borobetaine gives the key boryl radical that reacts with the α-(trifluoromethyl)styrene forming the initial C–B bond. Then a radical-polar crossover mechanism releases fluoride to provide a difluoroalkene product bearing the aminoborane synthetic handle. The difluoroalkene motif is of interest as a potent carbonyl bioisostere that has been shown to enhance biological activity and reactivity. The presence of the aminoborane moiety allows further functionalization such as Suzuki–Miyaura cross-coupling of the borylated products, which is demonstrated using complex aryl bromides. Various post-functionalizations demonstrate difluoroalkene-aminoboranes to be valuable building blocks for the construction of complex, high-value molecules.
Sodium Nitrite (NaNO2): An Expressive and Efficient Nitrating/Nitrosating Reagent in Organic Synthesis.
Authors: Carlos I Lamark , Barbosa Euzébio Guimarães , Jordão Alessandro Kappel
Published: December 2024

This graphical review provides a concise overview of the main organic chemical reactions reported in scientific works that used sodium nitrite as a nitrating/nitrosating agent capable of acting on various reactive substrates for the functionalization and synthesis of a wide variety of useful organic molecules.
Market equilibrium with management costs and implications for insurance accounting
Authors: Florig Michael , Gossner Olivier
Published: December 2024

We examine a general equilibrium investment model in which agents incur management costs for holding assets. We characterize the influence of these costs on equilibrium prices as a weighted average of these costs for market participants. We then propose a correction method for this influence in valuation procedures used under regulatory frameworks, such as Solvency II. For insurers subject to Solvency II, the accounting correction amounts to approximately €130 billion, the equivalent of 1.8% of investments or 14% of own funds. These results not only contribute to the understanding of management costs in market equilibrium, but also highlight a distortion in current practices which discourages the holding of assets that are expensive to manage and typically inaccessible directly by policyholders.
Fundamentals and applications of the skyrmion Hall effect
Authors: Yang Sheng , Zhao Yuelei , Zhang Xichao , Xing Xiangjun , Du Haifeng , Li Xiaoguang , Mochizuki Masahito , Xu Xiaohong , Åkerman Johan , Zhou Yan
Published: December 2024

Magnetic skyrmions are promising for future spintronic devices due to their nanoscale size, high thermal stability, and mobility at low current densities. However, their practical applications may be limited by the skyrmion Hall effect (SkHE), which causes skyrmions to deflect from the direction of the driving current. The SkHE usually results in annihilation of skyrmions due to the destructive skyrmion–boundary interactions. In this review, we provide a comprehensive overview of the fundamentals of the SkHE as well as the recent advances in manipulation and suppression of the SkHE in various types of magnetic materials. Additionally, we introduce some SkHE-free topological spin textures, such as skyrmioniums and hopfions. This review covers the following aspects: origin of the SkHE and its implications on spintronics, manipulation of the SkHE by external magnetic fields and geometrical engineering, and properties of SkHE-free spin textures. The review concludes by highlighting future research directions and challenges, suggesting that magnetic skyrmions and related topological spin textures will be essential for upcoming electronic and spintronic applications.
Upgraded space and time resolved visible spectroscopic diagnostic on ADITYA-U tokamak
Authors: Modi Dipexa , Chowdhuri M. B. , Yadava N. , Kumar A. , Ramaiya N. , Gauttam A. , Rajvanshi U. , Rathor M. , Patel S. , Sheeba R. R. , Mayya K. B. K. , Pathak S. K. , Ghosh J.
Published: December 2024

Poloidal asymmetries in neutral and impurity ion temperatures and particle and impurity transports have been observed in many tokamaks. To investigate these asymmetries, space-resolved visible spectroscopic diagnostic of the ADTIYA-U tokamak has been upgraded to measure the spatial profile of Hα and impurities spectral line profile, ion temperature, and plasma rotation from both low and high field sides of the plasma, simultaneously with a better spatial resolution. This has been done by developing a linear array of 15 optical fibers as compared to the present linear array of nine fibers having a core diameter of 400 μm and coupling it to the entrance slit of a 1 m long high-resolution spectrometer of the existing diagnostic. A sCMOS detector with a larger height has also been employed to record 15 tracks as compared to the nine tracks when the spectrometer was coupled to a CCD detector having a size of 26.6 × 6.6 mm. The spatial profile of the Hα spectral line from the low and high field sides of the ADITYA-U plasma has been now recorded at every 20 ms to investigate neutral particle dynamics.
Berwald m-Kropina spaces of arbitrary signature: Metrizability and Ricci-flatness
Authors: Heefer Sjors
Published: December 2024

The (pseudo-)Riemann-metrizability and Ricci-flatness of Finsler spaces with m-Kropina metric F = α1+mβ−m of Berwald type are investigated. We prove that the affine connection of F can locally be understood as the Levi–Civita connection of some (pseudo-)Riemannian metric if and only if the Ricci tensor of the canonical affine connection is symmetric. We also obtain a third equivalent characterization in terms of the covariant derivative of the 1-form β. We use these results to classify all locally metrizable m-Kropina spaces whose 1-forms have a constant causal character. In the special case where the first de Rham cohomology group of the underlying manifold is trivial (which is true of simply connected manifolds, for instance), we show that global metrizability is equivalent to local metrizability and hence, in that case, our necessary and sufficient conditions also characterize global metrizability. In addition, we further obtain explicitly all Ricci-flat, locally metrizable m-Kropina metrics in (3 + 1)D whose 1-forms have a constant causal character. In fact, the only possibilities are essentially the following two: either α is flat and β is α-parallel, or α is a pp-wave and β is α-parallel.
Brownian non-Gaussian polymer diffusion in non-static media
Authors: Zhang Xiao , Wang Heng , Deng Weihua
Published: December 2024

In nature, essentially, almost all the particles move irregularly in non-static media. With the advance of observation techniques, various kinds of new dynamical phenomena are detected, e.g., Brownian non-Gaussian diffusion. This paper focuses on the dynamical behavior of the center of mass (CM) of a polymer in non-static media and investigates the effect of polymer size fluctuations on the diffusion behavior. First, we establish a diffusing diffusivity model for polymer size fluctuations, linking the polymer size variation to the birth and death process, and introduce co-moving and physical coordinate systems to characterize the position of the CM for a polymer in non-static media. Next, the important statistical quantities for the CM diffusing diffusivity model in non-static media, such as mean square displacement (MSD) and kurtosis, are obtained by adopting the subordinate process approach, and the long-time asymptotic behavior of the MSD in the media of different types is specifically analyzed. Finally, the bivariate Fokker–Planck equation and the Feynman–Kac equation corresponding to the diffusing diffusivity model are detailedly derived and solved through the deep backward stochastic differential equation (BSDE) method to confirm the correctness of the derived equations.
Fiber formation mechanisms of jet-assisted wet spinning (JAWS)
Authors: Pan Zehao , Venkateswaran Barath , Nunes Janine K. , Brun Pierre-Thomas , Stone Howard A.
Published: December 2024

In fiber spinning of photopolymers, surface tension limits the diameter of the fiber that can be produced due to the Rayleigh–Plateau instability. Submerging a pre-fiber jet in a miscible environment liberates the system from capillary effects, thus allowing the jet to be stretched into thin threads without instability. In this work, we systematically investigated a spinning method using miscible liquids, called jet-assisted wet spinning (JAWS), where stretching is achieved by a nearby submerged liquid jet. The diameter of the pre-fiber jet is a function of its flow rate and position relative to the assisting submerged liquid jet. A particular case where the main jet is modeled as the Landau–Squire jet is used to demonstrate the tracer-like thinning behavior of the pre-fiber jet. Experiments show that buoyancy has a significant impact on the pre-fiber jet diameter because of its influence on the entrainment trajectory. Overall, our results demonstrate the potential for the parallelization of JAWS for high-throughput fiber production.
Interactions and asymptotic analysis of N-soliton solutions for the n-component generalized higher-order Sasa–Satsuma equations
Authors: Lin Zhuojie , Yan Zhenya
Published: December 2024

In this paper, we systematically study the N-solitons and asymptotic analysis of the integrable n-component third–fifth-order Sasa–Satsuma equations. We conduct the spectral analysis on the (n+2)-order matrix Lax pair to formulate a Riemann–Hilbert (RH) problem, which is used to generate the N-soliton solutions via the determinants. Moreover, we visually represent the interaction dynamics of multi-soliton solutions and analyze their asymptotic behaviors. Finally, we present the higher-order N-soliton solutions by dealing with the RH problem with higher-order zeros. These results will be useful to further analyze the multi-soliton structures and design the related physical experiments.
Detection of Parkinson’s disease using nocturnal breathing signals based on multifractal detrended fluctuation analysis
Authors: Dai Zhong , Liu Shutang , Liu Changan
Published: December 2024

Parkinson’s disease (PD) is a highly prevalent neurodegenerative disorder that poses a significant challenge in terms of accurate and cost-effective diagnosis. This study focuses on the use of fractal features derived from nocturnal breathing signals to diagnose PD. Our study includes 49 individuals with Parkinson’s disease (PD group), 49 relatively healthy individuals without PD (HC group), 49 individuals without PD but with other diseases (NoPD group), as well as 12 additional PD patients and 200 healthy individuals for testing. Using multifractal detrended fluctuation analysis, we extracted fractal features from nocturnal breathing signals, with logistic regression models applied to diagnose PD, as demonstrated in receiver operating characteristic curves. Eight fractal features show significant diagnostic potential for PD, including generalized Hurst exponents for the Airflow, Thorax, and Abdomen signals and the multifractal spectrum width of the SaO2 signal. Finally, the area under the receiver operating characteristic curve (AUC) of the training data set of the PD and HC groups for all four signals is 0.911, and the AUC of the testing data set is 0.929. These results demonstrate the potential of this work to enhance the accuracy of PD diagnosis in clinical settings.
Multi-frame x-ray radiography and image tracking for quantification of expansion in laser-driven tin ejecta microjets
Authors: Sun Yuchen , Hammons Joshua , Champion Daniel , Das Pinaki , Gunawidjaja Ray , Li Yuelin , Schuman Adam , Sinclair Nicholas , Toyoda Yoshimasa , Willey Trevor , Saunders Alison M. , Eggert Jon H. , Pino Jesse
Published: December 2024

One regime of experimental particle-laden flow study involves ejecta microjets—often defined as a stream of micrometer-scale particles generated through shock interaction with a non-uniform surface and generally travel above 1 km/s. In order to capture the change in characteristics as a function of propagation time, we apply a multi-frame x-ray radiography platform to observe and track the jet transport dynamics. A synchrotron x-ray source allows us to perform quantitative analyses and comparisons between the eight images captured by the imaging system. Observation of a single jet through time allows the use of a cross correlation algorithm to independently track various regions within the jet and quantify the jet expansion over time using normalized area and normalized areal density values. Through a comparison with the calculated values of ballistic transport, these findings show less expansion than expected for ballistically transporting particles. This work combines multi-frame synchrotron radiography with image tracking to establish a foundation for future studies on jet transport and particle interaction dynamics.
A table-top high-sensitivity gyroscope based on slow light and cavity enhanced photon drag
Authors: She Min , Tang Jiangshan , Xia Keyu
Published: December 2024

A high-sensitivity gyroscope is vital for both investigation of the fundamental physics and monitoring of the subtle variation of Earth’s behaviors. However, it is a challenge to realize a portable gyroscope with sensitivity approaching a small fraction of the Earth’s rotation rate. Here, we theoretically propose a method for implementing a table-top gyroscope with remarkably high sensitivity based on photon drag in a rotating dielectric object. By inserting an Er3+-doped glass rod in a Fabry–Pérot optical cavity with only 20 cm length, we theoretically show that the giant group refractive index and the narrowing cavity linewidth due to slow light can essentially increase the nonreciprocal phase shift due to the photon drag to achieve a rotation sensitivity of 26 frad/s/Hz. This work paves the way to accurately detect tiny variations of the Earth’s rotation rate and orientation and even can test the geodetic and frame-dragging effects predicted by the general relativity with small-volume equipment.
Oscillatory motion of two confined interacting particles settling under thermal convection: A lattice Boltzmann study
Authors: Ghannam Anas , Alazzam Anas , Abu-Nada Eiyad
Published: December 2024

This study investigated the sedimentation of two oscillating cold circular particles within a confined heated channel using the lattice Boltzmann method. The main objective was to investigate the effects of mixed convection, initial particle positioning, and wall confinement on particle behavior under different thermal regimes. In particular, this work sought to explain the mutual interactions between particles in the presence of these effects. Such an investigation is highly significant due to its widespread relevance in various natural and industrial processes involving particle transport. The four-way coupled model was validated against several classical benchmarks, including the drafting-kissing-tumbling interaction. The results demonstrated the critical role of initial particle positioning in promoting oscillatory motion. The reattachment of particle wakes leads to pronounced oscillations and vortex shedding in the trailing particle, especially when the particles are close. While these oscillations enhance the heat transfer coefficient, inter-particle collisions tend to suppress it. The results further revealed a decrease in the average Nusselt number for both particles below two, suggesting potential overestimation in the literature's correlation models. Furthermore, the Magnus force increasingly dominates drag forces as the Grashoff number increases. Notably, the influence of the trailing particle on the leading particle was observed exclusively during particle-wall collisions when close to the leading particle. Overall, this study highlighted the significant impact of thermal forces with wall confinement on particle motion across various thermal regimes, providing valuable insights into complex particle behavior and sedimentation patterns.
Modeling transport of hydrogel particles through porous media: An energy method and experimental guide
Authors: Li Shuaijun , Yu Hong-hui
Published: December 2024

The transport of soft particles through porous media is critical in natural and industrial processes, yet quantifying the relationship between pressure drop and key parameters such as particle size, concentration, and flow rate remains challenging. Using an energy-based method, we derive a governing equation for pressure by balancing energy dissipation from frictional and viscous losses with energy input. The model reveals exponential dependences of pressure drop on particle concentration and porous medium length, and a double exponential dependence on the ratio of particle size to pore throat size. A characteristic length emerges, beyond which the pressure increases sharply, indicating a plugging effect. Incorporating a velocity-dependent friction coefficient further uncovers a nonlinear pressure–flow rate relationship, deviating from Darcy’s law. Validated against experimental data, the model provides a comprehensive framework for understanding particle transport in porous media, with applications to filtration, drug delivery, and enhanced oil recovery.
Cascading failure dynamics on higher-order networks with load redistribution
Authors: Wu Zongning , Yang Jiaying , Fan Ying , Zhou Jianlin , Yu Chongchong
Published: December 2024

The phenomenon of load redistribution in complex networks has garnered extensive attention due to its profound impact and widespread occurrence. In recent years, higher-order structures have offered new insights into understanding the structures and dynamic processes of complex networks. However, the influence of these higher-order structures on the dynamics of load redistribution, cascade failures, and recovery processes remains to be fully explored. In this study, we propose the load redistribution model with higher-order structures and recovery strategies of cascade failure based on functional upgrading and reconstruction mechanisms. In the cascading failure process with load redistribution and higher-order recovery strategies, we find that higher-order structures can induce a discontinuous phase transition at the low proportion of load redistribution, and the dynamic process displays a dual character of being robust yet fragile. These findings have been examined in both real and classical modeled networks. Interestingly, the largest connected component exhibits three distinct modes as the attack ratio increases at high densities of higher-order structures and recovery mechanisms.
Variance-based wave function optimization within the unrestricted doubly occupied configuration interaction framework: A half-projection treatment
Authors: Garcia Javier , Alcoba Diego R. , Torre Alicia , Lain Luis , Oña Ofelia B. , Massaccesi Gustavo E.
Published: December 2024

The energy-variance-based optimization procedures have proven to be useful tools to describe N-electron spectra. However, the resulting wave functions usually present spin-contaminant contributions. The goal of this work is to reduce the spin contamination of the results arising from the unrestricted doubly occupied configuration interaction method in its energy variance minimization version [Alcoba et al., J. Chem. Phys. 160, 164107 (2024)]. We propose to incorporate the half-projection technique, which allows removing the spin components with even or odd spin quantum number of an approximate N-electron wave function, into the framework of the unrestricted doubly occupied configuration interaction treatment. This implementation can be carried out following several possible ways, whose results are analyzed in detail, in order to show the behavior of each procedure. Numerical determinations performed on selected strongly correlated N-electron systems, in ground and excited states, allow us to assess the most suitable procedure.
Kinetic equation of turbulence from the Boltzmann equation
Authors: Saveliev V. L.
Published: December 2024

We have shown how the kinetic equation for the velocity distribution function of an ensemble of turbulent velocities can be rigorously obtained from the Boltzmann kinetic equation with the classical collision integral. Compared to the Boltzmann equation on the left-hand side, the resulting kinetic equation of turbulence contains ten additional terms. Also, instead of the frequency of molecular collisions νcoll, the collision integral in the kinetic equation of turbulence includes the collision frequency νtp, which is significantly less than the frequency of molecular collisions. There are two key steps we have undertaken in obtaining the kinetic equation of turbulence. First, we used the invariance of the collision integral of the Boltzmann equation with respect to the Gaussian transformations. Second, we introduced the idea of fragmentation of turbulent flows into turbulent fluid quasiparticles. Each such quasiparticle is described by an equilibrium distribution of molecular velocities with fluctuating mean velocity. Also, each quasiparticle is characterized by its size, which is in the range of length scales larger than the mean free path of molecules λ and less than the typical length of spatial variation in the turbulence distribution function.
Exploring the heat transfer performance and vortex-induced vibration characteristics of cylinders near a heated surface
Authors: Ding Lin , Fu Yitong , Liu Dong , Ran Jingyu
Published: December 2024

To effectively harness vortex-induced vibration (VIV) for enhancing heat dissipation from a hot wall, this paper presents a series of studies on the VIV behavior of a cylinder near a wall and its heat transfer characteristics. The focus is on the effects of near-wall distance and the spacing ratio between cylinders in tandem on vibration response and heat transfer performance. Detailed analyses are provided for the amplitude–frequency response, lift–drag ratio, temperature distributions, averaged Nusselt number, and near-wake vortex structures. The research shows that a very narrow near-wall distance can partially suppress cylinder vibration and reduce the transport of cold fluid between the cylinder and the hot wall. Conversely, an excessively large near-wall distance diminishes the positive impact on heat transfer. For cylinders in tandem, strong interaction between the upstream and downstream cylinders at small spacing ratios leads to significant fluctuations in the averaged temperature on the wall. Specifically, the averaged temperature on the wall dropped to 326.41 K when S/D = 10.0 and U* = 6. At larger spacing ratios, the upstream cylinder exerts a shielding effect on the downstream cylinder, inhibiting its vibration and reducing its ability to enhance heat transfer through VIV. When U* ≥ 7, the averaged temperature on the wall initially decreases and then increases as the spacing ratio increases. The results indicate that cylinders in tandem with transverse free vibration achieve optimal heat transfer efficiency at H = 3.0D and S/D = 10.0.
Training stiff neural ordinary differential equations with implicit single-step methods
Authors: Fronk Colby , Petzold Linda
Published: December 2024

Stiff systems of ordinary differential equations (ODEs) are pervasive in many science and engineering fields, yet standard neural ODE approaches struggle to learn them. This limitation is the main barrier to the widespread adoption of neural ODEs. In this paper, we propose an approach based on single-step implicit schemes to enable neural ODEs to handle stiffness and demonstrate that our implicit neural ODE method can learn stiff dynamics. This work addresses a key limitation in current neural ODE methods, paving the way for their use in a wider range of scientific problems.
Controllable droplet velocity: Exploration of droplet transport based on discharge plasma
Authors: Li Dingchen , Li Chuan , Liang Tingyu , Li Jiawei , Yang Zhiwen , Fu Qixiong , Zhang Ming , Yang Yong , Yu Kexun , Du Yaping , Zhao Xiangen
Published: December 2024

Droplet transport assumes a crucial role in domains such as atmospheric governance, water resource development, drug delivery, medical analysis and detection, as well as the development of biosensors. Currently, droplet transport is accomplished through established chemical environments and structural gradients, yet it fails to precisely control the motion state of droplets. This paper presents an innovative approach for transporting droplets by means of discharge plasma, which governs the start, stop, and velocity of the droplets by modulating the discharge power. We employ discharge plasma to charge and polarize droplets and form gradient electric fields and gradient charges in space for driving droplets. Eventually, we achieved directional transport of diverse droplets via this method, which holds significant potential application value for controlling droplet motion.
The effects of hyperparameters on deep learning of turbulent signals
Authors: Tirchas Panagiotis , Drikakis Dimitris , Kokkinakis Ioannis W. , Spottswood S. Michael
Published: December 2024

The effect of hyperparameter selection in deep learning (DL) models for fluid dynamics remains an open question in the current scientific literature. Many authors report results using deep learning models. However, better insight is required to assess deep learning models' behavior, particularly for complex datasets such as turbulent signals. This study presents a meticulous investigation of the long short-term memory (LSTM) hyperparameters, focusing specifically on applications involving predicting signals in shock turbulent boundary layer interaction. Unlike conventional methodologies that utilize automated optimization techniques, this research explores the intricacies and impact of manual adjustments to the deep learning model. The investigation includes the number of layers, neurons per layer, learning rate, dropout rate, and batch size to investigate their impact on the model's predictive accuracy and computational efficiency. The paper details the iterative tuning process through a series of experimental setups, highlighting how each parameter adjustment contributes to a deeper understanding of complex, time-series data. The findings emphasize the effectiveness of precise manual tuning in achieving superior model performance, providing valuable insights to researchers and practitioners who seek to leverage long short-term memory networks for intricate temporal data analysis. The optimization not only refines the predictability of the long short-term memory in specific contexts but also serves as a guide for similar manual tuning in other specialized domains, thereby informing the development of more effective deep learning models.
Dual role of Te ions as electron traps and hole traps in ferroelectric Sn2P2S6 crystals
Authors: Gustafson T. D. , Scherrer E. M. , Giles N. C. , Rumi M. , Grabar A. A. , Halliburton L. E.
Published: December 2024

Tin hypothiodiphosphate (Sn2P2S6) is a ferroelectric semiconductor with electro-optic and photorefractive relevance. The lattice contains Sn2+ ions and (P2S6)4− anionic groups. In the present work, an Sn2P2S6 crystal is doped with Te during growth. Our results show that the Te ions occupy Sn sites and S sites, where they serve as electron and hole traps, respectively. Electron paramagnetic resonance (EPR) spectra from five trapped holes and one trapped electron are observed at low temperatures after exposure to 633 nm light. Spin-Hamiltonian parameters are extracted from the angular dependence of each spectrum. Holes are localized on (P2TeS5)4− units and form (P2TeS5)3− anions, with the five defects corresponding to Te on different S sites within the anion. These defects have large g shifts caused by the tellurium spin–orbit coupling parameter. Four of the five also have an isotropic hyperfine interaction with one Sn ion, which suggests that they have an adjacent Sn vacancy (leaving just one close Sn neighbor). Three trapped-hole spectra are photoinduced at 20 K and two appear after removing the light, warming to 120 K, and then returning to 20 K. Electrons are trapped in pairs at Te4+ ions occupying Sn2+ sites when the crystal is exposed to 633 nm light while at 20 K. The Te2+ ions that are formed have no observable EPR spectrum. Warming to 100 K releases one electron from Te2+ ions that have an adjacent Sn vacancy, and an EPR spectrum from Te3+ ions (5s25p) is seen when the crystal is returned to lower temperatures.
Structural stability and thermodynamics of artistic composition
Authors: Chan San To , Fried Eliot
Published: December 2024

Inspired by the way that digital artists zoom out of the canvas to assess the visual impact of their works, we introduce a conceptually simple yet effective metric for quantifying the clarity of digital images. This metric contrasts original images with progressively “melted” counterparts, produced by randomly flipping adjacent pixel pairs. It measures the presence of stable structures, assigning the value zero to completely uniform or random images and finite values for those with discernible patterns. This metric respects the color diversity of the original image and withstands image compression and color quantization. Its suitability for diverse image analysis problems is demonstrated through its effective evaluation of textural images, the identification of structural transitions in physical systems like the Potts model, and its consistency with color theory in digital arts. This allows us to demonstrate that color in visual art functions as a state variable, akin to the spin configuration in magnets, driving artistic designs to transition between states with distinct clarity. When combined with the Shannon entropy, which quantifies color diversity, the structural stability metric can serve as a navigation tool for artists to explore pathways on the complex structural information landscape toward the completion of their artwork. As a practical demonstration, we apply our metric to refine and optimize an emote design for a video game. The structural stability metric emerges as a versatile tool for extracting nuanced structural information from digital images, which may enhance decision-making and data analysis across scientific and creative domains.
Hierarchical gradients of multiple timescales in the mammalian forebrain
Authors: Song Min , Shin Eun Ju , Seo Hyojung , Soltani Alireza , Steinmetz Nicholas A. , Lee Daeyeol , Jung Min Whan , Paik Se-Bum
Published: December 2024

Many anatomical and physiological features of cortical circuits, ranging from the biophysical properties of synapses to the connectivity patterns among different neuron types, exhibit consistent variation along the hierarchical axis from sensory to association areas. Notably, the temporal correlation of neural activity at rest, known as the intrinsic timescale, increases systematically along this hierarchy in both primates and rodents, analogous to the increasing scale and complexity of spatial receptive fields. However, how the timescales for task-related activity vary across brain regions and whether their hierarchical organization appears consistently across different mammalian species remain unexplored. Here, we show that both the intrinsic timescale and those of task-related activity follow a similar hierarchical gradient in the cortices of monkeys, rats, and mice. We also found that these timescales covary similarly in both the cortex and basal ganglia, whereas the timescales of thalamic activity are shorter than cortical timescales and do not conform to the hierarchical order predicted by their cortical projections. These results suggest that the hierarchical gradient of cortical timescales might represent a universal feature of intracortical circuits in the mammalian brain.
Long-range
Atoh1
enhancers maintain competency for hair cell regeneration in the inner ear
Authors: Shi Tuo , Kim Yeeun , Llamas Juan , Wang Xizi , Fabian Peter , Lozito Thomas P. , Segil Neil , Gnedeva Ksenia , Crump J. Gage
Published: December 2024

During tissue regeneration, lineage-related cells can switch their fate to replace missing cells. This cell plasticity is particularly prominent in more regenerative vertebrates such as zebrafish, yet the molecular basis by which cells transdifferentiate into another cell type upon injury remains unclear. Here, we investigate the epigenetic basis of regenerative transdifferentiation in the inner ear, where supporting cells (SCs) generate mechanosensory hair cells (HCs) upon damage. By comparing the chromatin landscapes in regenerative zebrafish and green anole lizards versus nonregenerative mice, we identified a class of enhancers that function in progenitors to generate HCs and then are selectively maintained in SCs of regenerative vertebrates to regenerate HCs. In particular, we uncovered a syntenic class of long-range enhancers for
Atoh1
, a master transcription factor for HC differentiation. In the absence of injury, these enhancers maintain accessibility in SCs through adulthood but are prevented from driving zebrafish
atoh1a
expression through Notch repression. Deletion of these enhancers not only impaired
atoh1a
expression and HC formation during development but also blocked the ability of SCs to transdifferentiate into HCs during regeneration. Moreover, defects were specific to the inner ear versus the lateral line, revealing distinct mechanisms of regeneration in these mechanosensory organs. These findings reveal a class of regenerative enhancer that maintains competency of inner ear SCs to upregulate
atoh1a
and transdifferentiate into HCs upon damage. We propose that the continued accessibility of developmental enhancers for one cell fate in lineage-related cells may be a common theme underlying adult cell plasticity in regenerative vertebrates.
Editorial: Capacitating One Health in Eastern and Southern Africa
Authors: Richards Shauna
Published: December 2024

This collection of case studies outlines the status of One Health in twelve countries in Eastern and Southern Africa considering four thematic areas: (i) research and innovation, (ii) governance, (iii) education, and (iv) implementation. The cases demonstrate each country’s results alongside their challenges and priorities for One Health.

Information

© The Author 2024
“Since When Do Gos Speak Francanglais?”: Youth Slang and Gender Ideologies in a Cameroonian YouTube Series
Authors: Telep Suzie
Published: December 2024

This article analyzes the semiotic representations of gender through the language practices of Cameroonian youth observed in Tu Know Ma Life (You know my life), a YouTube series popular among the French Cameroonian diaspora that follows the daily life of nine young middle- and upper-class Cameroonian immigrants (five women and four men) living in Paris. This series is regarded by its audience as an authentic representation of Cameroonian identity, partly due to its remarkable use of Francanglais, a hybrid youth slang spoken in Cameroon. I analyze how the mediatized representation of Francanglais practices in the first season of the YouTube series contributes to the linguistic construction of gender differentiations. I argue that through the highly gendered use of Francanglais and French by women and men, the series reproduces hegemonic gender ideologies while reinforcing the ideological association between Francanglais and hegemonic heterosexual masculinity.
Metric symmetry by design in general relativity
Authors: Toth Viktor T
Published: December 2024

The usual derivation of Einstein’s field equations from the Einstein–Hilbert action is performed by silently assuming the metric tensor’s symmetric character. If this symmetry is not assumed, the result is a new theory, such as Einstein’s attempted Unified Field Theory or Moffat’s Nonsymmetric Gravitational Theory. Explicitly enforcing the constraint by means of a Lagrange-multiplier term restores Einstein’s field equations, but the multiplier appears as an additional, unconstrained antisymmetric term. We briefly discuss the possible significance of this term with respect to a nonvanishing cosmological angular momentum, a sourced spin current, the nonsymmetric nature of the Einstein pseudotensor characterizing the energy–momentum of the gravitational field, and possible implications on attempts to obtain a quantum theory of gravity.
Increasing spin–orbit torque efficiency by doping Pt: sub-monolayer insertions versus alloys
Authors: Janssens W , Carpenter R , Nguyen V D , Cai K , Agati M , Favia P , De Boeck J , Wostyn K , Couet S , Talmelli G
Published: December 2024

Spin–orbit torque magnetoresisitive random-access memory (SOT-MRAM) is a promising candidate as a non-volatile SRAM replacement. However, one of the biggest challenges that limits the SOT-MRAM application, is the relatively high current that is needed to switch the free layer. Pt is a promising SOT track material due to its low resistivity and compatibility with back end of line (BEOL) processes, though it has relatively low SOT-efficiency. A possible route to increase the SOT-efficiency of Pt is to dope it with another material. In this work, a comparative study is conducted between Pt with sub-monolayer insertions (local doping) and Pt-alloys (global doping), referred to as PtX. The structural differences between them lead to a different SOT-efficiency trend with respect to the content of the PtX layer. It is shown that in the Pt/X-insertions, a SOT-efficiency increase is obtained up to three sub-monolayer insertions and is relatively independent of the material X. On the other hand, the SOT-efficiencies in Pt-alloys are highly dependent on the material X. Compared to pure Pt, our results show that the SOT-efficiency of PtCu-alloys increases up to about three times, whereas PtCr-alloys show no significant enhancement. Furthermore, PtCu is a promising route towards BEOL compatible SOT-MRAMs, since it is shown that it can maintain the perpendicular magnetic anisotropy of 1 nm Co after 400 ∘C annealing, whilst maintaining an increased SOT-efficiency.
Simulation of metal nanoparticles growth in methane atmosphere of arc discharge: comparison to experiment
Authors: Nemchinsky V , Musikhin S , Raitses Y
Published: December 2024

A direct current arc discharge in a methane atmosphere is a scalable and sustainable method to produce metal-carbon core–shell nanoparticles and single-walled carbon nanotubes, where a metal catalyst can be continuously supplied through evaporation of an anode made from the catalyst material. The size of catalyst particles is of critical importance as it can affect the synthesis yield and properties of nanotubes and core–shell nanoparticles. This study presents a numerical model describing the formation and growth of metal particles for the conditions representative of the arc discharge with an evaporating iron anode at near-atmospheric pressure of a methane-rich atmosphere. The model incorporates carbon adsorption to the metal surface and explains the limiting effect of carbon coverage on the size of metal nanoparticles. The predicted particle sizes are compared with experimental observations. The model also predicts higher concentrations of metal particles with the increasing partial pressure of methane.
Faraday rotation in a cavity integrated with layered van der collinear antiferromagnetic material
Authors: Da Haixia , Ye Huapeng
Published: December 2024

Two dimensional layered van der Waals (vdW) ferromagnetic (FM) and anti FM materials enable the alternative candidates for establishing the next-generation magnetooptical (MO) devices. However, the explorations of the MO effects are primarily focused on the layered FM materials and their nanostructures. How the MO responses behave in the structures with vdW layered anti FM materials remain largely unknown. Here, we identify that a layered collinear antiferromagnet supports the nontrivial MO Faraday rotation (FR) angle in the presence of the electric field instead of magnetic field due to its lifted spin degeneracy and asymmetric band structure at different valleys, whose value is comparable with those of vdW layered ferromagnets and closely correlates with the size of the electric field. Specifically, the FR angle of the layered collinear antiferromagnet can be substantially enhanced via integrating it into a cavity structure, which promises the chance of improving their MO performance. Our result highlights the fundamental opportunities of utilizing the collinear antiferromagnets for various MO applications ranging from magnetometry to high density holographic data storage.