bluuebunny/crossref_metadata_2025 huggingface dataset:
Convective and absolute instabilities of double-diffusive convection with shear
Authors: Lu Cailei , Zhang Mengqi , Luo Kang , Yi Hongliang
Published: June 2024

In this study, we investigate the spatiotemporal instability of double-diffusive convection with and without a Couette flow, focusing mainly on the characters of transverse rolls. In the absence of shear, double-diffusive convection is always absolutely unstable even in the oscillatory instability regime, which is different from other flows that can also take the form of oscillatory convection. In the pure diffusive convection, before the transition from the oscillatory instability to steady instability, a saddle shift phenomenon is observed, which is related to the subcritical bifurcation of the steady branch. The presence of shear breaks the symmetry of oscillatory instability and along the neutral stability curve the spatiotemporal evolution of disturbance is determined by the competition between the shear intensity and the phase speed of oscillatory eigenmode traveling upstream. Therefore, as the shear intensity increases a transition from the absolute instability to the convective instability is expected, whereas as buoyancy strengthens the absolute instability eventually sets in again. On the other hand, the spatiotemporal instability of the sheared fingering convection is similar to the sheared Rayleigh–Bénard convection, in which the flow always undergoes a transition from the convective instability to absolute instability. In this case, increasing the Prandtl number or decreasing the diffusivity ratio between the two components, the region of convective instability expands due to the increasing viscous dissipation caused by the shear flow.
Lead-free perovskite/ZnO heterostructure for flexible visible-blind ultraviolet photodetection
Authors: Zhao Xinhong , Dai Jinyu , Dong Jixiang , Tao Yu , Chen Jiahuan , Song Xiaoxian , Fu Zhendong , Sun Wenbao , Yan Zaoxue
Published: June 2024

With the increasing demand for wearable, portable, and implantable optoelectronic devices, flexible photodetectors have become the hotspots of scientific pursuit. In this work, a flexible heterostructure photodetector was fabricated through a combination of perovskite CsCu2I3 nanorods and ZnO quantum dots by a facile solution method. The heterostructure combines the good bending resistance, low dark current, and excellent photoelectric conversion efficiency of CsCu2I3 nanorods with the high electron mobility of ZnO quantum dots; CsCu2I3 NRs act as the light compensating material and hole collector, while ZnO serves as an electron transport channel. This combination results in stronger UV absorption and reduced influence of visible light, achieving ultraviolet-to-visible rejection ratios of as high as 8 × 102. The photodetector exhibits superior performance in the visible-blind ultraviolet region, boasting an on–off ratio of 102, a tenfold increase compared to single-component CsCu2I3 NR photodetectors. Its responsivity and specific detectivity, at 1.62 A/W and 4.13 × 1011 Jones, respectively, outperform the single-component CsCu2I3 NRs by 40 and 23 times and surpass the single-component ZnO photodetectors by 102 times. The response time is about 50% shorter than that of the single-component CsCu2I3 and ZnO photodetectors. This photodetector also shows excellent flexibility and environmental and mechanical stability after a series of sharp bends. The results indicate that the CsCu2I3/ZnO heterostructure provides a promising alternative for high-performance flexible UV optoelectronics.
Detached eddy simulation of the interaction between acoustics and flame dynamics during the transition before and after longitudinal thermoacoustic instability in a multi-element liquid rocket engine
Authors: Liu Yuanzhe , Wang Zhuopu , Ao Wen , Guan Yu , Liu Peijin
Published: June 2024

In this study, we present the first numerical evidence of multiple bifurcation processes occurring in a multi-element model liquid rocket engine before and after the longitudinal thermoacoustic instability regime, as we vary the oxidizer inlet temperature within the range of 400–1400 K. To accurately capture the non-premixed turbulent combustion process, a comprehensive three-dimensional compressible detached eddy algorithm was employed, incorporating a two-step methane/oxygen chemical reaction kinetic mechanism based on OpenFOAM. After validating the numerical framework and achieving grid independence, we focus on (1) investigating the transition routes of system dynamics and (2) analyzing the spatiotemporal evolution of multiple jet combustion flow fields during the multi-bifurcation process. Our results indicate that the system dynamics undergoes two successive bifurcating processes. During the first bifurcation (400 K ≤ T ≤ 800 K), the system dynamics transitions into a full period-1 oscillation through intermittency. In the second bifurcation (1200 K ≤ T ≤ 1400 K), the system shifts from a limit cycle state back to a combustion noise state. The complex coupling mechanism between injectors is further elucidated through frequency spectrum results of radial velocity and temperature near the initial shear layer in the wakes of different injectors, especially the symmetry-breaking response between different injector jets. The analysis of snapshots and flame index also reveals the spatiotemporal evolution of combustion flow fields, specifically highlighting vortex dynamics, heat release, and combustion modes that potentially contribute to thermoacoustic instability.
Study on bridge tower-induced sudden wind and its impact on running performance of high-speed train
Authors: Wang Ming , Zheng Yuhao , Wang Zuxiang , He Haonan , Li Xiaozhen
Published: June 2024

Combined with computational fluid dynamics analysis method and coupled vibration analysis method, the aerodynamic shielding effect of tower of long-span sea-crossing bridge on high-speed trains is analyzed from the aspects of flow field distribution, aerodynamic characteristics, and dynamic response. Based on k–omega shear stress transport turbulence model, a three-dimensional numerical simulation model of train-tower-girder is established. Considering the influence of bridge tower width, train speed, and crosswind speed, how the bridge tower changes the aerodynamic characteristics of the train by causing local sudden wind is discussed, and the average fluctuation amplitude (Δm) and influence width (d) are defined to quantify the tower-induced aerodynamic shielding effect. Meanwhile, the further influence of shielding effect on train dynamic response is discussed by the comprehensive wind-train-track-bridge coupled analysis system. The results show that the bridge tower greatly changes the wind environment around the train with it passes through the bridge tower area, resulting in a significant and sudden change in the aerodynamic characteristics of the train. Larger tower width and smaller yaw angle (e.g., higher train speed and lower crosswind speed) will increase the influence width and sudden change amplitude of tower-induced shielding effect on trains' aerodynamic coefficients. The further influence of tower-induced sudden wind on car body acceleration and wheel load reduction ratio of high-speed train shows a wider width than that on train aerodynamic characteristics.
Aerodynamic characteristics of a square cylinder in transverse oscillating flows
Authors: Wang Xincong , Li Qiusheng , Li Ming , Lu Bin
Published: June 2024

The present study investigates the aerodynamic characteristics of a square cylinder subjected to transverse oscillating flows. The inflow oscillating frequencies range from 0.25 to 2.00 times the natural Karman vortex shedding frequency. The inflow oscillating intensities are within 5%–20%. Flow resonance between the inflow oscillation and Karman vortex shedding is identified by lift force spectra and verified by dynamic mode decomposition of velocity fields. The range of inflow frequencies conducive to flow resonance is centered around the natural Karman vortex shedding frequency and widens as the inflow fluctuating intensity increases, reaching a span of 0.5 to 1.5 times the natural Karman vortex shedding frequency at the intensity of 20%. The fluctuating lift force coefficients exhibit significant enhancement within the central region of the resonance frequency range, contrasting with lower values observed at the boundaries of this range (similar to non-resonance cases). The enhancement is attributed to intensified shear-layer flapping motion, which is quantitively estimated by the velocities at leading edges. In non-resonance cases and resonance cases with lower inflow frequencies, the root mean square pressure coefficients increase at the center of the leeward wall, resulting in a more uniform distribution of base pressures. Conversely, in resonance cases with higher inflow frequencies, the root mean square pressure coefficients exhibit a sharp decrease from the trailing edge to the center of the leeward wall. This phenomenon coincides with an expanded vertical separation between the Karman vortices of opposite directions in the wake region.
Steady-state probabilities for Markov jump processes in terms of powers of the transition rate matrix
Authors: Frezzato Diego
Published: June 2024

Several types of dynamics at stationarity can be described in terms of a Markov jump process among a finite number N of representative sites. Before dealing with the dynamical aspects, one basic problem consists in expressing the a priori steady-state occupation probabilities of the sites. In particular, one wishes to go beyond the mere black-box computational tools and find expressions in which the jump rate constants appear explicitly, therefore allowing for a potential design/control of the network. For strongly connected networks admitting a unique stationary state with all sites populated, here we express the occupation probabilities in terms of a formula that involves powers of the transition rate matrix up to order N − 1. We also provide an expression of the derivatives with respect to the jump rate constants, possibly useful in sensitivity analysis frameworks. Although we refer to dynamics in (bio)chemical networks at thermal equilibrium or under nonequilibrium steady-state conditions, the results are valid for any Markov jump process under the same assumptions.
Rewriting American uniqueness
Authors: Bouyahi Imen
Published: June 2024

Barack Obama is widely held to be the first sitting president to explicitly articulate the rhetoric of American exceptionalism. This paper uses the framing analysis methodology to explore his reconstruction of the exceptional American identity in a set of his public speeches and statements. It analyses the framing devices, such as lexical choices, metaphors and catchphrases, as well as the reasoning devices he used to reproduce new representations of American exceptionalism. Results point that Barack Obama’s ideational construct of American uniqueness resists the taken-for-granted narrative of America as a nation better than the rest of the world. His framing of the exceptional American identity is rather deeply rooted in John Winthrop’s image of the conditional shining of the city upon a hill. It conveys meanings of responsibility, hard work and commitment to common good as conditions for the fulfilment of an exceptionally “leading American self”. This paper contributes to both literatures on the discursive performance of the idea of American exceptionalism in the discourse of Barack Obama and the ongoing process of defining and redefining such a highly contested value in the American political discourse.
Saying “sorry” in online language
Authors: Yang Jia
Published: June 2024

This study conducts a pragmatic analysis of 192 apologies that were made by retailers in response to customer complaints posted on a leading Chinese online shopping website. Each collected apology is coded for the components of the apology and the strategies used to build rapport. The choice of the apology components and the exhibited rapport-building strategies are interpreted in the light of wider work in the field of politeness in Chinese. Results of this study extend the pragmatic analyses of public apologies by identifying the distinctive features of apologies occurring on Chinese online shopping websites, i.e., relatively infrequent use of the statement of responsibility and the greater use of offers of repair. Although the language on Chinese online shopping websites is often considered informal, the study found that a number of linguistic components are used by the online sellers as forms of politeness to repair the relationship with the complainers.
Political Satire and Collective Reproduction: The Power of Political Nicknames in Hong Kong
Authors: Kwong Ying-ho
Published: June 2024

The existing literature on political satire has focused primarily on the effects on audiences and their responses to satirical messages, neglecting the exploration of the implications of these effects. This article takes a reproduction perspective and argues that audiences regenerate and spread satirical messages to continuously denounce a political figure. By examining the circulation of “689,” the humorous nickname of former chief executive C. Y. Leung in Hong Kong, this article introduces a new conceptual framework called the “collective reproduction” process, which includes three processes: (1) production, (2) circulation, and (3) reproduction. This framework is used to analyze how the opposition effectively utilized this nickname to criticize the leader throughout his term of office. Theoretical contributions include providing political satire with an ongoing approach that facilitates its circulation. Empirically, the case of Hong Kong enriches the understanding of opposition movements within the context of political satire.
A novel 3D magnetic circuit method for calculating shielding factors of rectangular magnetically shielded rooms
Authors: Lu Yan , Qiu Shengjie , Sun Jinji , Zhang Lu , Tang Jiqiang
Published: June 2024

Rectangular magnetically shielded rooms (MSRs) are favored for their construction simplicity and efficient space usage. However, current rectangular MSRs lack an effective shielding factor (SF) theoretical system due to their inherent asymmetric geometry and process defects such as door gap. Therefore, an effective three-dimensional (3D) magnetic circuit method for calculating the SF of rectangular MSRs is proposed in this paper. Firstly, the theoretical model for the 3D magnetic circuit of rectangular MSRs is established, and the SF in three directions is derived. Secondly, the theoretical model is modified by introducing demagnetization factors to further improve the calculation accuracy of the SF based on the magnetization theory. Finally, formula systems for the SF considering door gap are derived, and their effect is also analyzed. To validate the proposed method, two rectangular MSRs with distinct structures are tested using a constructed experimental platform. The results show that the discrepancy between the calculated SF and the tested SF is less than 7%, affirming the efficacy of the proposed methodology. This method can be applied to rectangular MSRs of different sizes, and provide a valuable theoretical guidance for the construction of MSRs.
Lithium titanate synaptic device imitating lithium-ion battery structure
Authors: Liao Ye , Chen Gongying , Yu Jiulong , Huang Wei , Lin Guangyang , Wang Jianyuan , Xu Jianfang , Li Cheng , Chen Songyan
Published: June 2024

With the growing prevalence of neuromorphic computing algorithms, there is a growing need for electronic synaptic devices. In this study, using Li4+x
Ti5O12 (LTO) as the resistive switching layer, C as the lithium ions storage layer, and Li1+x
Al
x
Ti2−x
(PO4)3 (LATP) as ions transmission layer, a synaptic device is designed with the structure of Pt/C/LATP/LTO/PtSi to imitate the lithium-ion battery. Variation of the thickness of the LATP layer in the LTO device is explored to show the impact on the device’s synaptic performance. With a LATP thickness of 100 nm, the LTO synaptic device exhibits a high potentiation/depression cyclic stability of over 50 cycles, improved potentiation/depression linearity and smoothness. The synaptic potentiation/depression is ascribed to migration of lithium ions from the LTO layer. A conductance relaxation characteristic of the device is explained by battery self-discharge phenomenon. The battery effect in the LTO device also led to generation of electromotive force. The study of battery-imitating LTO synaptic device offers new perspectives on the connection between battery and analog synaptic device.
Majorana fermions in Kitaev chains side-coupled to normal metals
Authors: Soori Abhiram
Published: June 2024

Majorana fermions, exotic particles with potential applications in quantum computing, have garnered significant interest in condensed matter physics. The Kitaev model serves as a fundamental framework for investigating the emergence of Majorana fermions in one-dimensional systems. We explore the intriguing question of whether Majorana fermions can arise in a normal metal (NM) side-coupled to a Kitaev chain (KC) in the topologically trivial phase. Our findings reveal affirmative evidence, further demonstrating that the KC, when in the topological phase, can induce additional Majorana fermions in the neighboring NM region. Through extensive parameter analysis, we uncover the potential for zero, one, or two pairs of Majorana fermions in a KC side-coupled to an NM. Additionally, we investigate the impact of magnetic flux on the system and calculate the winding number -a topological invariant used to characterize topological phases.
Different KNN parameters on road surface extraction from UAV-based point cloud under several machine learning algorithms
Authors: Biçici Serkan
Published: June 2024

Accurate road surface from a three-dimensional (3D) point cloud depends on various parameters. One crucial parameter is the set of point features. Point features enable classification by capturing characteristics of the surface on which the points are located. These features are calculated based on the closest points surrounding each point. In this study, the K-nearest neighbors algorithm (KNN) was applied to identify these closest points. The KNN algorithm requires only one input, the number of closest points (k). Eight different point features were developed using different k values, and their impact on road surface classification from the 3D point cloud was investigated. It was observed that there is no significant improvement in classification accuracy until a certain k value. However, better classification accuracy was achieved after a certain k value. The effect of different k values was also investigated under different training sample structures and machine learning (ML) algorithms. When training samples were selected from a single location as a large group, similar classification accuracy was obtained across different k values. Conversely, when training samples were chosen from various regions in smaller groups rather than a single large group, improved classification was observed as the k value increased. Additionally, it was noted that five different ML algorithms-random forest, support vector machine, generalized linear model, linear discriminant analysis, and robust linear discriminant analysis-have almost similar performance under different k values. Finally, using the optimum k value, improvements of up to 4.543% and 6.601% in accuracy and quality measures, respectively, were found.
Silver-nanoparticle-modified nanocellulose synthesized by pyroligneous acid: cytotoxicity towards HaCat cells
Authors: Medeiros Lúcio C D , Sant’Anna Celso , Ferreira Veronica S , Gasparotto Luiz H S
Published: June 2024

In the present study, pyroligneous acid, also known as wood vinegar, has been employed as reducing and stabilizing agent in the synthesis of silver nanoparticles (AgNPs) anchored on nanocellulose (NC). The idea is to confer the latter bactericidal properties for its typical uses such as in cosmetics and food-packing. It has been demonstrated that AgNPs can be directly produced onto NC in one-pot fashion while dramatically enhancing the kinetics of AgNPs synthesis (2 h for reaction completion) in comparison to the NC-less counterpart (10 days for reaction completion). Furthermore, NC allowed for a narrower size distribution of AgNPs. NC-supported and non-supported AgNPs had sizes of 5.1 ± 1.6 nm and 16.7 ± 4.62 nm, respectively. Immortalized human keratinocytes (HaCat) cells were then employed as model to evaluate the cytotoxicity of the AgNPs-NC compound. The latter was found not to impact cell proliferation at any formulation, while decreasing the viability by only 6.8% after 72 h. This study contributes to the development of more environmentally benign routes to produce nanomaterials and to the understanding of their impact on cells.
Si anode with high initial Coulombic efficiency, long cycle life, and superior rate capability by integrated utilization of graphene and pitch-based carbon
Authors: Li Hai , Li Zhao , Qi Jie , Wang Ziyang , Liu Song , Long Yu , Tan Yan
Published: June 2024

A variety of strategies have been developed to enhance the cycling stability of Si-based anodes in lithium-ion batteries. Although significant progress has been made in enhancing the cycling stability of Si-based anodes, the low initial Coulombic efficiency (ICE) remains a significant challenge to their commercial application. Herein, pitch-based carbon (C) coated Si nanoparticles (NPs) were wrapped by graphene (G) to obtain Si@C/G composite with a small specific surface area of 11.3 m2 g−1, resulting in a high ICE of 91.2% at 500 mA g−1. Moreover, the integrated utilization of graphene and soft carbon derived from the low-cost petroleum pitch strongly promotes the electrical conductivity, structure stability, and reaction kinetics of Si NPs. Consequently, the synthesized Si@C/G with a Si loading of 54.7% delivers large reversible capacity (1191 mAh g−1 at 500 mA g−1), long cycle life over 200 cycles (a capacity retention of 87.1%), and superior rate capability (952 mAh g−1 at 1500 mA g−1). When coupled with a homemade LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode in a full cell, it exhibits a promising cycling stability for 200 cycles. This work presents an innovative approach for the manufacture of Si-based anode materials with commercial application.
Impurity transport study based on measurement of visible wavelength high-n charge exchange transitions at W7-X
Authors: Swee Colin , Geiger Benedikt , Ford Oliver , Nornberg Mark , O’Mullane Martin , Poloskei Peter , Reimold Felix , Romba Thilo , Wegner Thomas ,   the W7-X Team
Published: June 2024

A recently installed high-speed charge exchange diagnostic at the W7-X stellarator has been used to identify several high-n Rydberg emission lines near 500 nm following impurity injections. The wavelengths of observed high-n Rydberg transitions are independent of the impurity species and originate from ions with ionization states ranging from 14+ to 45+ suggesting that this approach can be applied to a variety of heavy impurities. Moreover, little to no passive signal is observed since the high-n energy levels are unlikely to be populated by electron impact excitation. The combination of the newly developed diagnostic and the observation of high-n Rydberg states provides spatially resolved, high-speed measurements of multiple charge states which are analyzed in a Bayesian inference framework to determine both impurity diffusion and convection profiles. Measurements from the 2023 experimental campaign conclusively show high diffusion and an inward pinch in the core, well above predictions by neoclassical theory.
Orbital stability of peakons and multi-peakons for a generalized quintic-septic Camassa-Holm type equation
Authors: He Dandan , Deng Tongjie , Zhang Kelei
Published: June 2024

In this paper, we consider the generalized quintic-septic Camassa-Holm (gqsCH) equation, which is actually an extension of the quintic CH equation and the septic CH equation. We first prove the existence of the single peakon. Then, by constructing certain Lyapunov functionals, we prove the stability of peakons in the energy space

H
1

(

R

)

H^1(\mathbb {R})

-norm. Finally, we also prove that the sum of

N
N

sufficiently decoupled peakons is orbitally stable in the energy space by using energy argument, combining the method of the orbital stability of single peakons with monotonicity of the local energy norm.
Compactness of Hamiltonian stationary Lagrangian submanifolds in symplectic manifolds
Authors: Chen Jingyi , Ma John Man Shun
Published: June 2024

In this work, we prove a compactness theorem on the space of all Hamiltonian stationary Lagrangian submanifolds in a compact symplectic manifold with uniform bounds on area and total extrinsic curvature. This generalizes the compactness theorems in Chen and Warren [J. Differential Geom. 126 (2024), pp. 65–97] and Chen and Ma [Var. Partial Differential Equations 60 (2021), Paper No. 75, 23].
The Negotiation of Differences in Faith on Board Cargo Vessels
Authors: Sampson Helen , Turgo Nelson , Cadge Wendy , Gilliat-Ray Sophie
Published: June 2024

Chapter 4 draws on shipboard observations and seafarers’ own accounts to describe how they frame and understand their own shipboard behaviours and how they navigate the tricky interactional terrain associated with working in strongly hierarchical mixed-nationality and mixed-faith crews. In many cases, this involves suppressing religious expression and practice, to an extent, and, in some cases, suppressing moral codes and deviating from pious behaviours in order to conform and ‘fit in’. The significance of faith is therefore obscured from ‘public’ view on board a vessel, yet, for many seafarers, faith plays a vital role in helping them to endure the harsh characteristics of a life at sea and to process and cope with the fear that is regularly associated with what is widely understood to be a dangerous occupation.
Easy recognition and high autoimmune hepatitis specificity of smooth muscle antibodies giving an actin microfilament immunofluorescent pattern on embryonal vascular smooth muscle cells
Authors: Granito Alessandro , Muratori Paolo , Pappas Georgios , Lenzi Marco , Czaja Albert J , Muratori Luigi
Published: June 2024

Smooth muscle antibodies (SMA) with anti-microfilament actin (MF-SMA) specificity are regarded as highly specific markers of type 1 autoimmune hepatitis (AIH-1) but their recognition relying on immunofluorescence of vessel, glomeruli, and tubules (SMA-VGT pattern) in rodent kidney tissue, is restricted by operator-dependent interpretation. A gold standard method for their identification is not available. We assessed and compared the diagnostic accuracy for AIH-1 of an embryonal aorta vascular smooth muscle (VSM) cell line-based assay with those of the rodent tissue-based assay for the detection of MF-SMA pattern in AIH-1 patients and controls. Sera from 138 AIH-1 patients and 295 controls (105 primary biliary cholangitis, 40 primary sclerosing cholangitis, 50 chronic viral hepatitis, 20 alcohol-related liver disease, 40 steatotic liver disease, and 40 healthy controls) were assayed for MF-SMA and SMA-VGT using VSM-based and rodent tissue-based assays, respectively. MF-SMA and SMA-VGT were found in 96 (70%) and 87 (63%) AIH-1 patients, and 2 controls (P < 0.0001). Compared with SMA-VGT, MF-SMA showed similar specificity (99%), higher sensitivity (70% vs 63%, P = ns) and likelihood ratio for a positive test (70 vs 65). Nine (7%) AIH-1 patients were MF-SMA positive despite being SMA-VGT negative. Overall agreement between SMA-VGT and MF-SMA was 87% (kappa coefficient 0.870, [0.789–0.952]). MF-SMA were associated with higher serum γ-globulin [26 (12–55) vs 20 g/l (13–34), P < 0.005] and immunoglobulin G (IgG) levels [3155 (1296–7344) vs 2050 mg/dl (1377–3357), P < 0.002]. The easily recognizable IFL MF-SMA pattern on VSM cells strongly correlated with SMA-VGT and has an equally high specificity for AIH-1. Confirmation of these results in other laboratories would support the clinical application of the VSM cell-based assay for reliable detection of AIH-specific SMA.
Functional near-infrared spectroscopy-based neurofeedback training regulates time-on-task effects and enhances sustained cognitive performance
Authors: Xu Jiayu , Zhang Wenchao , Yu Juan , Li Guanya , Cui Jianqi , Qi Haowen , Zhang Minmin , Li Mengshan , Hu Yang , Wang Haoyi , Min Huaqiao , Xu Fenggang , Xu Xiaodan , Zhu Chaozhe , Xiao Yi , Zhang Yi
Published: June 2024

Time-on-task effect is a common consequence of long-term cognitive demand work, which reflects reduced behavioral performance and increases the risk of accidents. Neurofeedback is a neuromodulation method that can guide individuals to regulate their brain activity and manifest as changes in related symptoms and cognitive behaviors. This study aimed to examine the effects of functional near-infrared spectroscopy-based neurofeedback training on time-on-task effects and sustained cognitive performance. A randomized, single-blind, sham-controlled study was performed: 17 participants received feedback signals of their own dorsolateral prefrontal cortex activity (neurofeedback group), and 16 participants received feedback signals of dorsolateral prefrontal cortex activity from the neurofeedback group (sham-neurofeedback group). All participants received 5 neurofeedback training sessions and completed 2 sustained cognitive tasks, including a 2-back task and a psychomotor vigilance task, to evaluate behavioral performance changes following neurofeedback training. Results showed that neurofeedback relative to the sham-neurofeedback group exhibited increased dorsolateral prefrontal cortex activation, increased accuracy in the 2-back task, and decreased mean response time in the psychomotor vigilance task after neurofeedback training. In addition, the neurofeedback group showed slower decline performance during the sustained 2-back task after neurofeedback training compared with sham-neurofeedback group. These findings demonstrate that neurofeedback training could regulate time-on-task effects on difficult task and enhance performance on sustained cognitive tasks by increasing dorsolateral prefrontal cortex activity.
Applying machine learning to characterize and extrapolate the relationship between seismic structure and surface heat flow
Authors: Zhang Shane , Ritzwoller Michael H
Published: June 2024

Geothermal heat flow beneath the Greenland and Antarctic ice sheets is an important boundary condition for ice sheet dynamics, but is rarely measured directly and therefore is inferred indirectly from proxies (e.g. seismic structure, magnetic Curie depth, surface topography). We seek to improve the understanding of the relationship between heat flow and one such proxy—seismic structure—and determine how well heat flow data can be predicted from the structure (the characterization problem). We also seek to quantify the extent to which this relationship can be extrapolated from one continent to another (the transportability problem). To address these problems, we use direct heat flow observations and new seismic structural information in the contiguous United States and Europe, and construct three Machine Learning models of the relationship with different levels of complexity (Linear Regression, Decision Tree and Random Forest). We compare these models in terms of their interpretability, the predicted heat flow accuracy within a continent and the accuracy of the extrapolation between Europe and the United States. The Random Forest and Decision Tree models are the most accurate within a continent, while the Linear Regression and Decision Tree models are the most accurate upon extrapolation between continents. The Decision Tree model uniquely illuminates the regional variations of the relationship between heat flow and seismic structure. From the Decision Tree model, uppermost mantle shear wave speed, crustal shear wave speed and Moho depth together explain more than half of the observed heat flow variations in both the United States [$r^2 \approx 0.6$ (coefficient of determination), $\mathrm{RMSE} \approx 8\, {\rm mW}\,{\rm m}^{-2}$ (Root Mean Squared Error)] and Europe ($r^2 \approx 0.5, \mathrm{RMSE} \approx 13\, {\rm mW}\,{\rm m}^{-2}$), such that uppermost mantle shear wave speed is the most important. Extrapolating the U.S.-trained models to Europe reasonably predicts the geographical distribution of heat flow [$\rho = 0.48$ (correlation coefficient)], but not the absolute amplitude of the variations ($r^2 = 0.17$), similarly from Europe to the United States ($\rho = 0.66, r^2 = 0.24$). The deterioration of accuracy upon extrapolation is caused by differences between the continents in how seismic structure is imaged, the heat flow data and intrinsic crustal radiogenic heat production. Our methods have the potential to improve the reliability and resolution of heat flow inferences across Antarctica and the validation and cross-validation procedures we present can be applied to heat flow proxies other than seismic structure, which may help resolve inconsistencies between existing subglacial heat flow values inferred using different proxies.
Coronavirus-related health literacy level of Turkish adults: psychometric properties of the scale
Authors: Soylar Pınar , Öztürk Fatma Özlem , Sönmez Sibel
Published: June 2024

An adequate level of health literacy enables people to adopt protective behaviors to cope with the COVID-19 pandemic. Validated instruments are desired to assess such reactions. This study aims to determine the level of health literacy and validity and reliability of the Coronavirus-Related Health Literacy Questionnaire (HLS-COVID-Q22) adapted to Turkish. The present study was carried out with 452 participants in Turkey using an online survey. The scale was translated from English to Turkish using the back-translation technique. The cultural adaptation was outlined in the context of establishing the validity and reliability of the instruments. A coronavirus-related health literacy measure was validated (HLS-COVID-Q22) for the Turkish population through exploratory factorial analysis, followed by a confirmatory factorial analysis. The coronavirus-related health literacy level of the participants was found to be 2.92 (± 0.51). Cronbach’s alpha internal consistency coefficient was found to be 0.95. A four-factor solution was confirmed with eigenvalues > 1.0, suggesting a four-factor solution and explaining 68.84% of the total variance. It was determined that the χ2/df and root mean square residual, root mean square error of approximation and comparative fit index values in the last model had a good fit and that the normed fit index, goodness-of-fit index and adjusted goodness-of-fit index values were acceptable. The coronavirus-related health literacy level of Turkish adults was moderate. HLS-COVID-Q22 was a reliable and valid instrument for measuring coronavirus-related health literacy in the Turkish population. Promoting population-based health literacy and making decisions on accurate and reliable information are important in coping with the epidemic.
Binary black holes population and cosmology in new lights: signature of PISN mass and formation channel in GWTC-3
Authors: Karathanasis Christos , Mukherjee Suvodip , Mastrogiovanni Simone
Published: June 2024

The mass, spin, and merger rate distribution of the binary black holes (BBHs) across cosmic redshifts provide a unique way to shed light on their formation channel. Along with the redshift dependence of the BBH merger rate, the mass distribution of BBHs can also exhibit redshift dependence due to different formation channels and dependence on the metallicity of the parent stars. We explore the redshift dependence of the BBH mass distribution jointly with the merger rate evolution from the third gravitational wave (GW) catalogue GWTC-3 of the LIGO–Virgo–KAGRA collaboration. We study possible connections between peak-like features in the mass spectrum of BBHs and processes related to supernovae physics and time delay distributions. We obtain a preference for short-time delays between star formation and BBH mergers. Using a power-law form for the time delay distribution ($(t^{\rm min}_d)^{d}$), we find d < −0.7 credible at 90  per cent interval. The mass distribution of the BBHs could be fitted with a power-law form with a redshift-dependent peak feature that can be linked to the pair instability supernovae (PISN) mass-scale MPISN(Z*) at a stellar metallicity Z*. For a fiducial value of the stellar metallicity Z* = 10−4, we find the $\rm M_{\rm PISN}(Z_*)=44.4^{+7.9}_{-6.3}$$\rm M_\odot$. This is in accordance with the theoretical prediction of the lower edge of the PISN mass-scale and differs from previous analyses. Although we find a strong dependence of the PISN value on metallicity, the model that we explored is not strongly favoured over those that do not account for metallicity as the Bayes factors are inconclusive. In the future with more data, evidence towards metallicity dependence of the PISN will have a significant impact on our understanding of stellar physics.
Data mining techniques on astronomical spectra data – III. Association analysis
Authors: Cai Jianghui , Zhang Mingxing , Yang Haifeng , Shi Chenhui , Zhou Lichan , He Yanting , Su Meihong , Zhao Xujun , Chen Jiongyu
Published: June 2024

Association analysis is an important task that aims to investigate correlations in astronomical spectral data and mine relationships between different data features. With the rapid development of various sky survey projects, multiple association analysis methods have been applied to efficiently investigate the correlation between spectral data. However, due to the different focuses of analysing the relationships within spectral data, the performance and applicability scenarios of association analysis methods vary. We present the third article in the series to provide a comprehensive review of algorithms for astronomical spectral association analysis. First, this paper outlines the ideas and applications of association analysis algorithms for astronomical spectra in the current literature. Secondly, experiments are conducted on a unified A-type stellar spectral data set constructed based on three different signal-to-noise ratios and data volumes to examine the performance of different algorithms in analysing the correlation between data features. The results indicate that association rule algorithms can more comprehensively and effectively uncover the correlations among different spectral features, while regression analysis algorithms offer a simpler and more intuitive approach to analysing relationships between features. The spectral data used in the experiments are obtained from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope. Finally, the source code of association analysis algorithms and manuals for usage are provided on GitHub.
Simultaneous derivation of galaxy physical properties with multimodal deep learning
Authors: Gai Mario , Bove Mario , Bonetta Giovanni , Zago Davide , Cancelliere Rossella
Published: June 2024

Upcoming telescopes and surveys will revolutionize our understanding of the Universe by providing unprecedented amounts of observations on extragalactic objects, which will require new tools complementing traditional astronomy methods, in particular machine learning techniques, and above all, deep architectures. In this study, we apply deep learning methods to estimate three essential parameters of galaxy evolution, i.e. redshift, stellar mass, and star formation rate (SFR), from a data set recently analysed and tailored to the Euclid context, containing simulated H-band images and tabulated photometric values. Our approach involved the development of a novel architecture called the FusionNetwork, combining two components suited to the heterogeneous data, ResNet50 for images, and a Multilayer Perceptron (MLP) for tabular data, through an additional MLP providing the overall output. The key achievement of our deep learning approach is the simultaneous estimation of the three quantities, previously estimated separately. Our model outperforms state-of-the-art methods: overall, our best FusionNetwork improves the fraction of correct SFR estimates from ∼70 to ∼80 per cent, while providing comparable results on redshift and stellar mass.
Improved prenatal assessment of kidney disease using multiple ultrasound features
Authors: Buffin-Meyer Bénédicte , Klein Julie , Aziza Jacqueline , Fernandez Manon , Feuillet Guylène , Seye Mouhamed , Buléon Marie , Fédou Camille , Camus Mylène , Burlet-Schiltz Odile , Martinovic Jelena , Saulnier-Blache Jean-Sébastien , Decramer Stéphane , Schanstra Joost P
Published: June 2024

Background

Congenital anomalies of the kidney and urinary tract (CAKUT), often discovered in utero, cover a wide spectrum of outcomes ranging from normal postnatal kidney function to foetal death. The current ultrasound workup does not allow for an accurate assessment of the outcome. The present study aimed to significantly improve the ultrasound-based prediction of postnatal kidney survival in CAKUT.

Methods

Histological analysis of kidneys of 15 CAKUT foetuses was performed to better standardize the ultrasound interpretation of dysplasia and cysts. Ultrasound images of 140 CAKUT foetuses with 2-year postnatal follow-up were annotated for amniotic fluid volume and kidney number, size, dysplasia and/or cysts using a standardized ultrasound readout. Association of ultrasound features and clinical data (sex and age at diagnosis) with postnatal kidney function was studied using logistic regression. Amniotic fluid proteome related to kidney dysplasia or cysts was characterized by mass spectrometry.

Results

Histologically, poor ultrasound corticomedullary differentiation was associated with dysplastic lesions and ultrasound hyperechogenicity was associated with the presence of microcysts. Of all ultrasound and clinical parameters, reduced amniotic volume, dysplasia and cysts were the best predictors of poor outcome (odds ratio 57 [95% confidence interval (CI) 11–481], 20 [3–225] and 7 [1–100], respectively). Their combination into an algorithm improved prediction of postnatal kidney function compared with amniotic volume alone (area under the receiver operating characteristics curve 0.92 [95% CI 0.86–0.98] in a 10-fold cross-validation). Dysplasia and cysts were correlated (Cramer's V coefficient = 0.44, P < .0001), but amniotic fluid proteome analysis revealed that they had a distinct molecular origin (extracellular matrix and cell contacts versus cellular death, respectively), probably explaining the additivity of their predictive performances.

Conclusion

Antenatal clinical advice for CAKUT pregnancies can be improved by a more standardized and combined interpretation of ultrasound data.
Applying Behavioral Learning Theory in Schools
Authors: Sprague Jeffrey
Published: June 2024

This chapter provides terms, concepts, and evidence-supported strategies for applying behavioral learning theory in schools. The chapter begins with a brief history of behavioral learning theory (also known as applied behavior analysis, or ABA), and then a section presenting basic concepts and definitions, including the components of the operant, stimulus control, reinforcement, and punishment. The main content of the chapter describes and illustrates ABA methods for teaching new behaviors (academic and behavioral) and for increasing or decreasing problematic behaviors via simple and multicomponent approaches. This includes methods for (a) establishing (and transferring) stimulus control (teaching new behaviors), (b) increasing behaviors via reinforcement, (c) promoting generalization and maintenance, (d) decreasing behaviors via punishment, and (e) multicomponent ABA interventions, which combine several basic ABA methods in a unified manner. Each method is defined with a simple example or research study provided to illustrate their use.
DWARF TILLER1 regulates apical–basal pattern formation and proper orientation of rice embryos
Authors: Tang Jingyao , Huang Xiaorong , Sun Mengxiang , Liang Wanqi
Published: June 2024

Body axis establishment is one of the earliest patterning events in plant embryogenesis. Asymmetric zygote division is critical for apical–basal axis formation in Arabidopsis (Arabidopsis thaliana). However, how the orientation of the cell division plane is regulated and its relation to apical–basal axis establishment and proper position of embryos in grasses remain poorly understood. By characterizing mutants of 3 rice (Oryza sativa) WUSCHEL HOMEOBOX9 (WOX9) genes, whose paralogs in Arabidopsis play essential roles in zygotic asymmetric cell division and cell fate determination, we found 2 kinds of independent embryonic defects: topsy-turvy embryos, in which apical–basal axis twists from being parallel to the longitudinal axis of the seed to being perpendicular; and organ-less embryos. In contrast to their Arabidopsis orthologs, OsWOX9s displayed dynamic distribution during embryo development. Both DWT1/OsWOX9A and DWL2/WOX9C play major roles in the apical–basal axis formation and initiation of stem cells. In addition, DWT1 has a distinct function in regulating the first few embryonic cell divisions to ensure the correct orientation of the embryo in the ovary. In summary, DWT1 acts in 2 steps during rice embryo pattern formation: the initial zygotic division, and with DWL2 to establish the main body axes and stem cell fate 2 to 3 d after pollination.
Strebel Differentials and String Field Theory
Authors: Ishibashi Nobuyuki
Published: June 2024

A closed string worldsheet of genus g with n punctures can be presented as a contact interaction in which n semi-infinite cylinders are glued together in a specific way via the Strebel differential on it, if $n\ge 1,\ 2g-2+n\gt 0$. We construct a string field theory of closed strings such that all the Feynman diagrams are represented by such contact interactions. In order to do so, we define off-shell amplitudes in the underlying string theory using the combinatorial Fenchel–Nielsen coordinates to describe the moduli space and derive a recursion relation satisfied by them. Utilizing the Fokker–Planck formalism, we construct a string field theory from which the recursion relation can be deduced through the Schwinger–Dyson equation. The Fokker–Planck Hamiltonian consists of kinetic terms and three-string interaction terms.
Mechanical Leaf Removal for Improved Botrytis Bunch Rot Control in Vitis vinifera ‘Pinot gris’ and ‘Pinot noir’ Grapevines in the Northeastern United States
Authors: Hed Bryan , Centinari Michela
Published: June 2024

Late-season bunch rot can cause substantial yield loss in grapevines grown in humid regions. Fruit-zone leaf removal has been widely used to reduce bunch rot and pesticide applications through improvements in canopy microclimate and grape cluster morphology. In this study, we evaluated whether mechanical leaf removal can be a valid alternative to a labor-intensive manual application by comparing prebloom manual (PB-MA) and mechanical (PB-ME) leaf removal. We also evaluated the effects of the timing of mechanical application, prebloom (PB-ME) versus fruit set (FS-ME), on fruit traits and bunch rot, caused by Botrytis cinerea. Our trials were conducted on two Vitis vinifera ‘Pinot noir’ and ‘Pinot gris’ vineyards in the Northeastern United States over two seasons (2017 to 2018). Major findings were overall consistent between cultivars and years. Leaf removal provided reductions in fruit-zone canopy density regardless of method or timing. In general, PB-ME provided similar shifts in cluster morphological traits to PB-MA, including lower number of berries per cluster, cluster compactness, and cluster weight compared with control (no leaf removal) vines. At harvest, both prebloom leaf removal methods equally reduced Botrytis bunch rot severity, whereas Botrytis bunch rot incidence in Pinot noir was lowest for PB-ME in 1 year and PB-MA in the next year. When comparing timing of mechanical leaf removal, FS-ME provided Botrytis bunch rot reductions similar to PB-ME, without effects on cluster weight. Thus, under our growing conditions, FS-ME was considered the best mechanical leaf removal option to help manage Botrytis bunch rot without causing undesirable yield reductions.