bluuebunny/crossref_metadata_2025 huggingface dataset:
Full-rank imaging detection of multi-frames of ultrasonic-guided waves in welded structural plate based on arc sparse array
Authors: Zhu Xinjie , Yao Sen , Deng Mingxi , Gao Yang
Published: January 2025

The utilization of ultrasonic-guided wave array imaging in the detection of weld structural plates holds significant importance. This study presents a novel approach for full-rank imaging of shear horizontal-guided wave arc sparse arrays in welding structure imaging detection, the paper discusses the mechanism behind the ultrasonic-guided wave arc sparse array, specifically focusing on its full-rank imaging of multi-frames (FRIMR) capabilities in the presence of weld scattering. The receiving aperture of the arc sparse array is analyzed and discussed using the amplitude matrix and time-transition matrix. Both synthetic aperture and FRIMR of the arc sparse array are examined. The research findings demonstrate that FRIMR detection using ultrasonic-guided wave arc sparse array effectively captures scattering information equivalent to the wavelength size in the imaging detection area. This results in an average SNR improvement of 39.2% in full-frame imaging compared to multi-frames imaging. The imaging experiment validates the feasibility of the proposed imaging principle, highlighting its potential for imaging detection of welded structures. The research presented in this paper serves as a crucial foundation for future studies and applications of array imaging detection using ultrasonic-guided waves in welded structural plates.
Cholesteric liquid crystal mixtures for the switchable smart windows and light shutters: electro-optical and dielectric behavior
Authors: Pooja  , Sharma Vandna , Kumar Pankaj
Published: January 2025

Cholesteric liquid crystal (CLC) mixtures with variable pitch lengths were prepared for the electrical switchable smart window and light shutter applications by taking varied concentrations (2.6, 3.0, 4.0, and 5.0 wt%) of chiral dopant (R1011) having helical twisting power 37.6 μm−1 and nematic E7 liquid crystal (LC). The morphological and electro-optical analysis of these CLC mixtures filled in 10 μm thick cells were observed and reported herein, the switching of initial planar (P) and initial focal conic (FC) to homeotropic (H) states as well as vice-versa. The operating voltage of the 2.6 wt% of chiral doped CLC cell was relatively lower among all the sample cells compared with other concentrations. The maximum contrast ratio (CR) was observed for 5.0 wt% chiral doped CLC cell with initial planar state. However, the best CR was observed in 2.6 wt% CLC cell with initial FC state. The comparative macroscopic views of the P, FC, and H states in the OFF and ON conditions of applied voltage for prepared CLC cells were observed for transparent and opaque states. Further, UV–visible spectroscopy was performed in the P, FC, and H states under the application of an externally applied field to observe the absorbance and band gap behavior of the fabricated CLC cells. Additionally, chiral concentration-dependent dielectric parameters with variable frequency in initial P and FC states of the fabricated cells were also reported. The temperature-dependent phase behavior of all the prepared cells exhibited a slight decrease in the isotropic phase of LC due to the doping of chiral dopants.
Gate-tunable photodetectors based on MoTe2/MoS2 heterostructures anti-ambipolar transistors
Authors: Yan Cong , Liu Hongxia , Yu Hao , Yang Hangtian
Published: January 2025

Anti-ambipolar transistors (AATs) are considered as a breakthrough technology in the field of electronics and optoelectronics, which is not only widely used in diverse logic circuits, but also crucial for the realization of high-performance photodetectors. The anti-ambipolar characteristics arising from the gate-tunable energy band structure can produce high-performance photodetection at different gate voltages. As a result, this places higher demands on the parametric driving range (ΔV
g) and peak-to-valley ratio (PVR) of the AAT. Here, we demonstrate a high-performance photodetector with anti-ambipolar properties based on a van der Waals heterojunction of MoTe2/MoS2. Flexible modulation of carrier concentration and transport by gate voltage achieves a driving voltage range ΔV
g as high as 38.4 V and a PVR of 1.6 × 102. Most importantly, MoTe2/MoS2 exhibits a pronounced gate-tunable photoresponse, which is attributed to the modulation of photogenerated carrier transport by gate voltage. The MoTe2/MoS2 heterojunction photodetector exhibits excellent performance, including an impressive responsivity of 17 A W−1, a high detectivity of 4.2 × 1011 cm Hz1/2 W−1, an elevated external quantum efficiency of 4 × 103%, and a fast response time of 21 ms. Gate-tunable photodetectors based on MoTe2/MoS2 heterostructures AAT have potential to realize optoelectronic devices with high performance, providing a novel strategy to achieve high-performance photodetection.
Impact of mercury vacancy states on Shockley–Read–Hall recombination in narrow gap HgCdTe
Authors: Kozlov D V , Ikonnikov A V , Mazhukina K A , Morozov S V , Gavrilenko V I , Mikhailov N N , Dvoretsky S A , Rumyantsev V V
Published: January 2025

Technologically relevant narrow-gap Hg1−x
Cd
x
Te is known to contain a considerable amount of mercury vacancies that supposedly degrade carrier lifetimes. Using a semiclassical approach with no adjustable parameters, we calculate the capture coefficients for acceptor states with different binding energies. Resulting Shockley–Read–Hall recombination times agree well with the experimental data and suggest that the operating temperature of Hg1−x
Cd
x
Te detectors with ∼20 µm cutoff can be elevated above 77 K.
Radial self-accelerating acoustic beam for three-dimensional helical motion of microparticles
Authors: Chen Di-Chao , Hao Jing , Wu Da-Jian , Cheng Ying , Liu Xiao-Jun
Published: January 2025

Radially self-accelerating acoustic beams (RSABs) with rotating field distributions enable three-dimensional manipulation of particles. Nevertheless, the generation of desired RSABs is always a challenge. In this study, we derive a general form for the RSABs with a rotating acoustic field. We investigate the correlation between acoustic intensity and phase distribution of the RSAB in-depth via theoretical calculations. Artificial structure plates carved with Archimedean spiral slits are designed to produce two-component RSABs (TRSABs). It is found that the number of main lobes, rotational speed, and initial position of the TRSAB can be modulated by simply changing the number of arms, initial radius, and relative angle of the two sets of spirals. The experimental and numerical demonstrations confirm the ability of artificial structure plates to generate TRSABs. Finally, simulations are performed to calculate the acoustic radiation force on Rayleigh polydimethylsiloxane particles in a TRSAB. The work presented here could greatly benefit acoustic particle three-dimensional trapping and manipulation.
Chalcogenide dual-core all-solid anti-resonant fiber polarization beam splitter operating at 3 μm band
Authors: Zhang Zhenlong , Guo Haitao , Li Jianshe , Zhao Yuanyuan , Li Shuguang , Xu Yantao , Chang Yanjie , Zhang Hao
Published: January 2025

For the first time, we proposed a polarization beam splitter (PBS) designed based on chalcogenide dual-core all-solid anti-resonance fiber (AS-ARF) and simulated it numerically using the finite element method (FEM). Two large cladding tubes are introduced to divide the fiber core into fiber cores A and B. Mode coupling and energy exchange between the two fiber cores are enabled through the gap g between the two large cladding tubes. By adjusting the structural parameters of the AS-ARF, polarization beam-splitting ability and single-mode characteristics can be obtained. The influence of the position of the nested tube within the large cladding tube on the performance of the PBS is further investigated. The numerical results show that the beam-splitting lengths of the two proposed PBSs are 9.5 cm and 8.2 cm, respectively, and the polarization extinction ratios (PERs) are −55.98 dB and −41.35 dB at 3 μm. In the wavelength range from 2.98 μm to 3.03 μm, both PBSs can simultaneously achieve polarization beam-splitting and single-mode characteristics. The proposed chalcogenide-based dual-core AS-ARF is a suitable candidate for PBS in the mid-infrared 3 μm band.
The performance of space-fractional quantum carnot engine
Authors: Zacky Muhammad Sulthan , Sukamto Heru , Yuwana Lila , Purwanto Agus , Latifah Eny
Published: January 2025

This paper investigates the impact of space-fractional on the performance of a quantum heat engine. A particle confined in a one-dimensional infinite potential well serves as the working substance. The fractional parameter is incorporated into the Schrodinger equation, allowing us to derive the quantized energy of the system. The engine operates on a Carnot-like thermodynamic cycle, with heat leakage included to evaluate its performance. The findings reveal that both the efficiency and power output depend not only on the fractional parameter but also on the initial width of the potential. Notably, there exists a critical value of the initial potential width where the fractional case outperforms the non-fractional case in terms of both efficiency and power output.
Robust adaptive extended target filtering based on multiplicative noise model
Authors: Wang Li , Chen Hui , Lian Feng , Wang Xuxin
Published: January 2025

This study proposes two novel methods for tracking extended target with elliptical shape under non-Gaussian noise conditions. To achieve this, an explicit nonlinear measurement equation is formulated by incorporating a multiplicative noise term that connects the target's kinematic and shape parameters with the measurements. This measurement equation is employed to derive a closed-form solution for the Student's t extended Kalman filter based on multiplicative noise model (St-EKF-MNM) with recursive measurement updates. To further optimize the target tracking performance, the Hessian matrix was used to deal with the nonlinearity in the measurement equation, further derive the Student's t second-order extended Kalman filter based on multiplicative noise model (St-SOEKF-MNM). The effectiveness and robustness of the proposed methods are demonstrated with simulation.
Energy-preserving methods for gyrocenter system in strong magnetic field
Authors: Ji Lun , Tang Yifa , Wang Bin , Zhu Beibei
Published: January 2025

We formulate second-order and fourth-order energy-preserving methods with two explicit corrections for gyrocenter system in a strong magnetic field

1

ϵ

B
(
X
)

where the

∥
B
(
X
)

∥

2

=
O
(
1
)

and ϵ < < 1. We theoretically show that the error bound of the two methods are independent of ϵ. The two explicit corrections are both manifold corrections. The first correction is confined to the manifold that the Hamiltonian at current time step should equal to the Hamiltonian at former time step and the second correction is confined to the manifold that the Hamiltonian at current time step should equal to the original Hamiltonian. Numerical experiments illustrate the impact of the ϵ on the phase orbit and the global error. Additionally, the numerical results show that the energy-preserving methods with the first correction show its advantage in long-term energy conservation than the energy-preserving methods without correction. The energy-preserving methods with the second correction behaves better in energy conservation than those with the first correction as the energy error of the former ones can be bounded by the machine precision over long time.
Insights into dark matter direct detection experiments: decision trees versus deep learning
Authors: López-Fogliani Daniel E. , Perez Andres D. , de Austri Roberto Ruiz
Published: January 2025

The detection of Dark Matter (DM) remains a significant challenge in particle physics. This study exploits advanced machine learning models to improve detection capabilities of liquid xenon time projection chamber experiments, utilizing state-of-the-art transformers alongside traditional methods like Multilayer Perceptrons and Convolutional Neural Networks. We evaluate various data representations and find that simplified feature representations, particularly corrected S1 and S2 signals as well as a few shape-related features including the time difference between signals, retain critical information for classification. Our results show that while transformers offer promising performance, simpler models like XGBoost can achieve comparable results with optimal data representations. We also derive exclusion limits in the cross-section versus DM mass parameter space, showing minimal differences between XGBoost and the best performing deep learning models. The comparative analysis of different machine learning approaches provides a valuable reference for future experiments by guiding the choice of models and data representations to maximize detection capabilities.
A DAQ system with low-dead-time, high-precision TDC for APD detection efficiency calibration
Authors: Ma S. , Jin G. , Chen L.
Published: January 2025

Correlated photon calibration based on spontaneous parametric down-conversion (SPDC) provides a highly precise means to calibrate the detection efficiency of avalanche photodiode (APD). During the calibration process of detection efficiency via SPDC, precise measurement of the arrival time of correlated photons and accurate photon counting are essential. To achieve this goal, a data acquisition (DAQ) system with low-dead-time, high-resolution Time-to-Digital Converter (TDC) was designed in this paper. This TDC is designed based on tapped delay line (TDL), which is implemented on Xilinx Kintex-7 series field programmable gate array (FPGA). This TDC can accurately measure the time of arrival of input signals. Upon arrival of a photon signal, the TDC rapidly generates a timestamp to record the arrival time of the photon signal. Utilizing these timestamps, time delay and accurate measurements of time intervals can be achieved. The specially designed TDC input stage structure and encoding algorithm enable the alternating propagation and sampling of `01' and `10' transitions on TDL. Coupled with a pipelined architecture, the TDC's dead time is close to one clock cycle, which is 2.33 ns in the current implementation version. The structure of mode recognition and triggering ensures that the TDC can correctly calibrate time measurements and count photon counts. Experimental results show that the TDC achieves an RMS precision of better than 11.08 ps, and this measurement precision is maintained over long time intervals (0–10 us). The reliability of this DAQ for photon counting has been verified through standard signal sources.
Existence results of non-local integro-differential problem with singularity under a new fractional Musielak–Sobolev space*
Authors: Cheng Yu , Bai Zhanbing
Published: January 2025

In this article, we construct a new fractional Musielak–Sobolev space designed to address the non-locality associated with the corresponding integro-differential operators. The completeness, reflexivity, and uniform convexity of this new space, along with an associated embedding theorem are established. As a practical application, we investigate the solvability of a class of non-local problems with singular nonlinearities under the new fractional Musielak–Sobolev space. Based on appropriate assumptions, we derive an existence result for two weak solutions utilizing the fibering method in form of the Nehari manifold. Furthermore, we provide two concrete operator examples within the framework of the fractional Musielak–Sobolev space as examples.
Suspended-core photonic crystal fibers for SERS detection of biomolecules
Authors: Issatayeva Aizhan , Mariyam Siddra , Kho Kiang Wei , Andersson-Engels Stefan , Cucinotta Annamaria
Published: January 2025

Photonic crystal fiber (PCF) can be used as a microfluidic platform for surface-enhanced Raman spectroscopy (SERS)-based measurement of different samples. PCF can provide a long area of interaction for light, metal nanoparticles (NPs), and analytes incorporated into its holes. This paper provides a COMSOL simulation model for suspended-core PCF used to evaluate the SERS intensity depending on the fiber’s geometry and NPs’ coverage density. The simulation is applied to compare three PCFs with varying sizes and lengths. SERS measurements of adenine and DNA validate the simulation outcomes and demonstrate the potential of PCFs for SERS-based detection of diverse samples.
The effect of travertine waste on the strength and insulation properties of foam concrete
Authors: Guven Huseyin , Inel Mehmet
Published: January 2025

Incorporating waste additives into foam concrete mixtures is a promising route to develop environmentally-friendly concrete production with tailored thermos-mechanical properties. In this paper, the effects of various fabrication parameters of foam concrete, including the type of waste additive, water/binder ratio, density of mixture, and incorporation of glass fibers were investigated. Foam concrete samples were fabricated using fly ash and travertine wastes, and the variations in their compressive strength, and thermal conductivity using various concrete mixture designs were measured. The obtained results show that foam concrete with fly ash additive tends to have higher compressive strength and thermal conductivity than foam concrete with travertine waste. However, the latter exhibits better thermal insulation properties, which tend to improve by adding glass fibers. This work defines the outlines for exploring the use of harmful wastes in fabricating foam concrete. It offers guidelines for developing improved foam concrete mixtures with tailored thermos-mechanical properties.
Simulations of the potential for diffraction enhanced imaging at 8 kev using polycapillary optics
Authors: Bittel Carmen A , MacDonald Carolyn A
Published: January 2025

Conventional x-ray radiography relies on attenuation differences in the object, which often results in poor contrast in soft tissues. X-ray phase imaging has the potential to produce higher contrast but can be difficult to utilize. Instead of grating-based techniques, analyzer-based imaging, also known as diffraction enhanced imaging (DEI), uses a monochromator crystal with an analyzer crystal after the object. Analyzer-based systems most commonly employ synchrotron sources to provide adequate intensity, and typically use higher photon energies. In this work, a simulation has been devised to assess the potential for a polycapillary-based system. A polycapillary collimating optic has previously been shown to greatly enhance the intensity of the beam diffracted from the monochromatizing crystal. Detailed simulation of the optic is computationally intensive and requires comprehensive knowledge of the internal shape of the optic, so a simple geometric model using easier to obtain optic output data was developed and compared to the more detailed simulation. After verification, refraction band visibility was used as a quality parameter to address the effectiveness of the polycapillary-based DEI system at x-ray photon energies of 8 and 17.5 keV. The result shows promise for a polycapillary-coupled analyzer-based system even at low x-ray photon energy.
Security of hybrid BB84 with heterodyne detection
Authors: Sidhu Jasminder S , Maggi Rocco , Pascazio Saverio , Lupo Cosmo
Published: January 2025

Quantum key distribution (QKD) promises everlasting security based on the laws of physics. Most common protocols are grouped into two distinct categories based on the degrees of freedom used to carry information, which can be either discrete or continuous, each presenting unique advantages in either performance, feasibility for near-term implementation, and compatibility with existing telecommunications architectures. Recently, hybrid QKD protocols have been introduced to leverage advantages from both categories. In this work we provide a rigorous security proof for a protocol introduced by Qi in 2021, where information is encoded in discrete variables as in the widespread Bennett Brassard 1984 protocol but decoded continuously via heterodyne detection. Security proofs for hybrid protocols inherit the same challenges associated with continuous-variable protocols due to unbounded dimensions. Here we successfully address these challenges by exploiting symmetry. Our approach enables truncation of the Hilbert space with precise control of the approximation errors and lead to a tight, semi-analytical expression for the asymptotic key rate under collective attacks. As concrete examples, we apply our theory to compute the key rates under passive attacks, linear loss, and Gaussian noise.
Theoretical and experimental analysis of phase noise in semiconductor lasers biased below threshold
Authors: de Zulueta Iker Pascual , Valle Angel
Published: January 2025

We report a theoretical and experimental study of phase noise in semiconductor lasers when the bias current is below the threshold value. The theoretical study is performed by using two types of rate equations, with additive and multiplicative noise terms. We find the conditions for which the evolution in those rate equations can be described by 1-dimensional and two dimensional Brownian motions, respectively. The main statistical differences between the additive and multiplicative noise models are then illustrated by using the simplified Brownian motion models. Additive and multiplicative noise models predictions are compared with measurements of the phase noise with a coherent receiver using a 90∘ optical hybrid. We develop a novel method to extract the phase noise directly from our measurements, that in contrast to the usual direct method is not based on the analysis of the phase noise difference. The method permits a direct visualization of the phase noise trajectories and a calculation of the averages and the distribution that is valid in the short-time limit. Our results are in very good agreement with the results obtained with the method based on the phase noise difference. Our experimental results show that the variance of the phase noise grows linearly in time and has Gaussian statistics, supporting the modelization of the phase noise statistics with the additive noise model.
Dynamic modeling and guidance analysis of a ferromagnetic continuum robot with geometric discretization and base linear motion
Authors: Mallahi Kolahi Pouya , Habibnejad Korayem Moharam
Published: January 2025

With the advancement of robotics in medicine in recent years, diverse and promising applications for ferromagnetic continuum robots (FCRs) have been introduced. These robots utilize an electromagnetic actuation system for movement and control, which leads to reduced tissue damage, significantly shorter surgery durations, and improved patient recovery times. Recent research in FCR modeling highlights the critical challenge of developing a dynamic model to assess system behavior in real-time, crucial for maximizing benefits in medical applications. In this paper, the geometric discretization method and Lagrange’s principle are used to derive the dynamic equations of a FCR under the influence of an external magnetic field. This approach enables the examination of the system’s behavior at any given moment, providing a suitable foundation for designing various controllers based on the model. Given the electromagnetic system used in steering the FCRs, an analysis of the magnetic field in both ideal and real conditions is conducted to enhance reliability for medical applications. Simulation results indicate that the robots deform in a direction different from the magnetic field direction, demonstrating non-planar deformation characteristics. Furthermore, comparison with experimental data demonstrates that the theoretical framework accurately predicts the robot’s deformation, with calculation errors less than 5%.
Twisted Patterson-Sullivan Measures and Applications to Amenability and Coverings
Authors: Coulon Rémi , Dougall Rhiannon , Schapira Barbara , Tapie Samuel
Published: January 2025

Let

Γ
′

>
Γ

\Gamma ’>\Gamma

be two discrete groups acting properly by isometries on a Gromov-hyperbolic space

X
X

. We prove that their critical exponents coincide if and only if

Γ
′

\Gamma ’

is co-amenable in

Γ
\Gamma

, under the assumption that the action of

Γ
\Gamma

on

X
X

is strongly positively recurrent, i.e. has a growth gap at infinity. This generalizes all previously known results on this question, which required either

X
X

to be the real hyperbolic space and

Γ
\Gamma

geometrically finite, or

X
X

Gromov hyperbolic and

Γ
\Gamma

cocompact. This result is optimal: we provide several counterexamples when the action is not strongly positively recurrent.
VirDetect-AI: a residual and convolutional neural network–based metagenomic tool for eukaryotic viral protein identification
Authors: Zárate Alida , Díaz-González Lorena , Taboada Blanca
Published: January 2025

This study addresses the challenging task of identifying viruses within metagenomic data, which encompasses a broad array of biological samples, including animal reservoirs, environmental sources, and the human body. Traditional methods for virus identification often face limitations due to the diversity and rapid evolution of viral genomes. In response, recent efforts have focused on leveraging artificial intelligence (AI) techniques to enhance accuracy and efficiency in virus detection. However, existing AI-based approaches are primarily binary classifiers, lacking specificity in identifying viral types and reliant on nucleotide sequences. To address these limitations, VirDetect-AI, a novel tool specifically designed for the identification of eukaryotic viruses within metagenomic datasets, is introduced. The VirDetect-AI model employs a combination of convolutional neural networks and residual neural networks to effectively extract hierarchical features and detailed patterns from complex amino acid genomic data. The results demonstrated that the model has outstanding results in all metrics, with a sensitivity of 0.97, a precision of 0.98, and an F1-score of 0.98. VirDetect-AI improves our comprehension of viral ecology and can accurately classify metagenomic sequences into 980 viral protein classes, hence enabling the identification of new viruses. These classes encompass an extensive array of viral genera and families, as well as protein functions and hosts.
High-dimensional partially linear functional Cox models
Authors: Chen Xin , Liu Hua , Men Jiaqi , You Jinhong
Published: January 2025

As a commonly employed method for analyzing time-to-event data involving functional predictors, the functional Cox model assumes a linear relationship between the functional principal component (FPC) scores of the functional predictors and the hazard rates. However, in practical scenarios, such as our study on the survival time of kidney transplant recipients, this assumption often fails to hold. To address this limitation, we introduce a class of high-dimensional partially linear functional Cox models, which accommodates the non-linear effects of functional predictors on the response and allows for diverging numbers of scalar predictors and FPCs as the sample size increases. We employ the group smoothly clipped absolute deviation method to select relevant scalar predictors and FPCs, and use B-splines to obtain a smoothed estimate of the non-linear effect. The finite sample performance of the estimates is evaluated through simulation studies. The model is also applied to a kidney transplant dataset, allowing us to make inferences about the non-linear effects of functional predictors on patients’ hazard rates, as well as to identify significant scalar predictors for long-term survival time.
Clinically meaningful eGFR slope as a surrogate endpoint differs across CKD stages and slope evaluation periods: the CKD-JAC study
Authors: Imaizumi Takahiro , Komaba Hirotaka , Hamano Takayuki , Nangaku Masaomi , Murotani Kenta , Hasegawa Takeshi , Fujii Naohiko , Nitta Kosaku , Isaka Yoshitaka , Wada Takashi , Maruyama Shoichi , Fukagawa Masafumi
Published: January 2025

Background

The slope of estimated glomerular filtration rate (eGFR) is a promising surrogate endpoint in patients with chronic kidney disease (CKD). However, current evidence is mainly derived from Western populations with CKD stages 1–3. In addition, stage-by-stage analysis has never been formally performed.

Methods

We analyzed data from the Chronic Kidney Disease Japan Cohort Study, which included a large proportion of patients with CKD stages 4 and 5. We estimated eGFR slopes over three evaluation periods (0.5, 1, and 2 years) using mixed effects models and examined their associations with kidney failure with replacement therapy across CKD stages.

Results

Of 2713 patients with an available 1-year eGFR slope, 985 subsequently initiated kidney replacement therapy. Overall, a slower eGFR decline was strongly associated with a lower risk of subsequent kidney failure with replacement therapy. The association was pronounced with higher baseline CKD stages and attenuated with shorter evaluation periods. The estimated deceleration in eGFR decline over 1 year associated with a 20% lower risk of subsequent kidney failure with replacement therapy was 1.91 (1.60–2.37), 1.12 (1.00–1.28), and 1.06 (0.81–1.60) ml/min/1.73 m2 per year in patients with CKD stages 3, 4, and 5, respectively.

Conclusion

Our results support the potential of eGFR slope as a surrogate across different stages of CKD in Asians and suggest that a shorter evaluation period than 2 years may be feasible for patients with late-stage CKD. Our findings provide valuable insights for the future design of clinical trials in CKD patients, especially those with more advanced CKD.
Imaging-based method to quantify left ventricular diastolic pressures
Authors: Smiseth Otto A , Fernandes Joao F , Ohte Nobuyuki , Wakami Kazuaki , Donal Erwan , Remme Espen W , Lamata Pablo
Published: January 2025

Aim

To establish an imaging-based method to quantify left ventricular (LV) diastolic pressures.

Methods/results

In 115 patients suspected of coronary artery disease, LV pressure was measured by micromanometers and images by echocardiography. LV filling pressure was measured as LV pre-atrial contraction pressure (pre-A PLV). Based on previous observations we hypothesized that pre-A PLV approximates the sum of minimum PLV and maximum transmitral pressure difference. Parameters used for pressure estimates included LV volumes and strain, left atrial strain, mitral flow velocities, systolic arterial cuff pressure and body mass index. Minimum PLV was estimated by predictors identified in a derivative cohort (n=81). Mitral pressure difference was calculated by a simplified Navier-Stokes equation. Accuracy of estimates of minimum PLV, pre-A PLV and end-diastolic PLV were investigated in a testing cohort (n=19). Patient-specific LV diastolic pressure curves were constructed by adjusting a reference curve according to pressure estimates at key diastolic events.

There was good agreement between estimated and measured pre-A PLV: Bias 0.0, limits of agreement <3.1 mmHg (±1.96SD). Estimated minimum PLV and end-diastolic PLV also showed good agreement with measured pressures. Furthermore, there was good agreement between measured and estimated LV diastolic pressure curves, quantified as mean LV diastolic pressure: Bias 0.2, limits of agreement <3.2 mmHg.

Conclusion

The proposed non-invasive method provided estimates of minimum PLV, pre-A PLV and end-diastolic PLV, each reflecting different features of diastolic function. Additionally, it provided an estimate of the LV diastolic pressure curve. Validation in larger populations with different phenotypes is necessary to determine the validity of the method in clinical practice.
Invading and range-expanding pink salmon inform management actions for marine species on the move
Authors: Dunmall Karen M , Bean Colin W , Berntsen Henrik H , Ensing Dennis , Erkinaro Jaakko , Irvine James R , Kendall Neala W , Kitching Tor , Langan Joseph A , Millane Michael , Oxman Dion S , Radchenko Vladimir I , Thorstad Eva B , Utne Kjell Rong
Published: January 2025

Species redistributions, whether resulting from invasions or range expansions, pose similar challenges for conservation and management. Redistribution impacts on host ecosystems and species combine with those from climate change, which are already acute at northern latitudes. Using pink salmon Oncorhynchus gorbuscha, which are native to the Pacific Ocean, we employ knowledge exchange to inform decision-making in non-native marine areas: they are expanding their range to the Arctic Ocean and are invasive in the Atlantic Ocean. The predicted future marine distribution of pink salmon focuses effort on where and when pink salmon are present and informs on potential interactions with native species. Management actions taken in the Atlantic Ocean to reduce invasive pink salmon are resource-intensive, but removed salmon could be a food resource. Addressing identified gaps regarding the invasion potential of pink salmon, interactions among pink salmon and other species, and current mitigation efforts would support forward-thinking management decisions given predictions of continued environmental change. We also highlight steps that can be taken immediately to coordinate actions and better inform responses. Managed for production in the Pacific and as an invasion in the Atlantic, pink salmon provide a tangible approach to informed decision-making through collaboration for marine species on the move.
Argos satellite transmitters enable billfish research at finer scales
Authors: Arostegui Martin C , Gaube Peter , Vo Amie , Thorrold Simon R , Braun Camrin D
Published: January 2025

Satellite transmitters that provide Doppler-based locations and telemeter data via the Argos satellite system have revealed a wealth of information on the movement ecology of diverse fauna such as marine mammals, turtles, and sharks. In contrast, satellite telemetry studies of bony fishes have almost exclusively relied on pop-up satellite archival tags (PSATs) that use light-based geolocation to estimate movements. However, track reconstructions based on light and other sensor data transmitted by PSATs exhibit positional error that is orders of magnitude higher than those from Argos Doppler-based locations, effectively limiting our understanding of bony fish movement ecology to coarse scales. Although PSATs continue to be the technological workhorse of billfish research, with more than 1000 data records published to date, a handful of pioneering studies have tried using tags capable of providing Argos Doppler-based locations to better understand these taxa. We assess the applicability of Argos satellite transmitters to study billfish in the context of their depth distribution and by comparing alternative tag attachment strategies and form factors. We present two case studies that highlight how these data can explicitly be used for fine-scale ecological and oceanographic research. This work culminates with the introduction of a new Smart Position and Temperature (SPOT) transmitting tag designed specifically for billfish and other pelagic fishes that has the potential to open new avenues of research, revealing dimensions of behavior that previously could not be investigated.
Proteins and pathways involved in inflammation are longitudinally associated with total body bone mineral density among primarily Hispanic overweight/obese adolescents and young adults
Authors: Beglarian Emily , Chen Jiawen Carmen , Li Zhenjiang , Costello Elizabeth , Wang Hongxu , Hampson Hailey , Alderete Tanya L , Chen Zhanghua , Valvi Damaskini , Rock Sarah , Chen Wu , Rianon Nahid , Aung Max T , Gilliland Frank D , Goran Michael I , McConnell Rob , Eckel Sandrah P , Lee Miryoung , Conti David V , Goodrich Jesse A , Chatzi Lida
Published: January 2025

BMD, an important marker of bone health, is regulated by a complex interaction of proteins. Plasma proteomic analyses can contribute to identification of proteins associated with changes in BMD. This may be especially informative in stages of bone accrual and peak BMD achievement (ie, adolescence and young adulthood), but existing research has focused on older adults. This analysis in the Study of Latino Adolescents at Risk for Type 2 Diabetes (SOLAR; n = 304; baseline age 8-13, 100% Hispanic) explored associations between baseline proteins (n = 653 proteins) measured with Olink plasma protein profiling and repeated annual DXA measures of BMD (average of 3.2 visits per participant). Covariate-adjusted linear mixed effect regression models were applied to estimate longitudinal protein—BMD associations using an adjusted p value cutoff (p < .00068). Identified proteins were imported into the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database to determine significantly enriched protein pathways. Forty-four proteins, many of which are involved in inflammatory processes, were associated with longitudinal changes in total body BMD, including several proteins previously linked to bone health such as osteopontin (SPP1) and microfibrillar-associated protein 5 (MFAP5; both p < .00068). These 44 proteins were associated with enrichment of pathways including PI3K-Akt signaling pathway and cytokine–cytokine receptor interaction, supporting results from existing proteomics analyses in older adults. To evaluate whether protein associations were consistent into young adulthood, linear mixed effect models were repeated in a young adult cohort (n = 169; baseline age 17-22; 62.1% Hispanic) with 346 available overlapping Olink protein measures. While there were no significant overlapping longitudinal protein associations between the cohorts, these findings suggest differences in protein regulation at different ages and provide novel insight on longitudinal protein associations with BMD in overweight/obese adolescents and young adults of primarily Hispanic origin, which may inform the development of biomarkers for bone health in youth.
Presidential Address 2024: The Value and Profits of Firms
Authors: Eeckhout Jan
Published: January 2025

The real growth of the stock market value of firms has increased from close to 0% on average per year between 1958 and 1980, to 5.2% between 1980 and today. This change coincides with the rise of market power and profits, starting in 1980. This paper proposes to decompose the value of firms based on profits (earnings) rather than dividends. Because firms on average pay out only half of profits in dividends, dividends poorly measure firm performance. I decompose the sources of the rise of the value of all publicly traded firms into the following categories: (1) the subjective and risk-free discount factor, (2) expected future profits, and (3) shareholder equity (retained earnings). I find that 20% of the rise is due to the discount factor and 80% is due to profits (45% current and future expected profits; 35% retained earnings). I build a general equilibrium model of the economy where firms have market power; I perform counterfactuals and evaluate the welfare implications. The objective is to study the impact of competition policy. If market power today dropped to the level of 1980, average stock market values would be 45% lower. Instead, if market power had never increased in 1980, the average stock values would be 80% lower.
Rationally Inattentive Statistical Discrimination: Arrow Meets Phelps
Authors: Echenique Federico , Li Anqi
Published: January 2025

When information acquisition is costly but flexible, a principal may rationally acquire information that favors one group over another. The former group faces incentives to invest in becoming productive, while the latter is discouraged from such investments. In turn, the principal largely overlooks the productivity differences between groups and primarily promotes the invested group, unless the underinvested group surprises him with a genuinely outstanding outcome. We show that, when attention costs are intermediate, investment costs are low, and investments are likely to succeed, the discriminatory equilibrium is the most preferred by the principal, despite all groups being ex-ante identical. Our results inform the discussion of affirmative action, implicit bias, and occupational segregation and stereotypes.
Aberrant accumulation of phosphorylated BRCA1 in brainstem-type and cortical-type Lewy bodies in Lewy body disease
Authors: Nakamura Masataka , Murakami Aya , Dickson Dennis W , Yakushiji Yusuke
Published: January 2025

BRCA1 plays important roles in several biological events during the DNA damage response (DDR). We aimed to determine whether cytoplasmic accumulation of BRCA1 or its phosphorylated form, pBRCA1, is specific to cytoplasmic inclusions in tauopathies, or if it also occurs in α-synuclein-positive inclusions in Lewy body disease (LBD). Using brain tissue from pure LBD, LBD with Alzheimer disease (AD) co-pathology (LBD-AD), and control cases, the immunohistochemical distributions of BRCA1, pBRCA1, its binding partner BARD1, and 53BP1 were examined. The results showed that pBRCA1 (Ser1423) and BARD1 accumulated in brainstem-type Lewy bodies (LBs), whereas only pBRCA1 (Ser1423) was present in cortical-type LBs. There was no significant difference in the frequency of pBRCA1 (Ser1423)-positive LBs between the pure LBD and LBD-AD cases. pBRCA1 (Ser1423) was minimally detected in neuronal nuclei in controls and was absent in neuronal nuclei in LBD cases. In control and LBD cases, 53BP1-immunoreactive deposits were present in the neuronal nuclei. Thus, DDR dysfunction due to cytoplasmic sequestration of pBRCA1 (Ser1423) may play a role in LBD pathogenesis. Additionally, the selective accumulation of BARD1 in brainstem-type LBs, but not cortical-type LBs, points to distinct mechanisms in the formation of these inclusion types, offering further insights into LBD pathology.
Accurate shear estimation with fourth-order moments
Authors: Park Andy , Li Xiangchong , Mandelbaum Rachel
Published: January 2025

As imaging surveys progress in exploring the large-scale structure of the Universe through the use of weak gravitational lensing, achieving sub-per cent accuracy in estimating shape distortions caused by lensing, or shear, is imperative for precision cosmology. In this paper, we extend the Fourier power function shapelets (FPFS) shear estimator using fourth-order shapelet moments and combine it with the original second-order shear estimator to reduce galaxy shape noise. We calibrate this novel shear estimator analytically to a sub-per cent level-accuracy using the AnaCal framework. This higher order shear estimator is tested with realistic image simulations, and after analytical correction for the detection/selection bias and noise bias, the multiplicative shear bias $|m|$ is below $3\times 10^{-3}$ (99.7 per cent confidence interval) for both isolated and blended galaxies. Once combined with the second-order FPFS shear estimator, the shape noise is reduced by $\sim 35~{{\ \rm per\ cent}}$ for isolated galaxies in simulations with Hyper Suprime-Cam and Vera C. Rubin Observatory Legacy Survey of Space and Time observational conditions. However, for blended galaxies, the effective number density does not significantly improve with the combination of the two estimators. Based on these results, we recommend exploration of how this framework can further reduce the systematic uncertainties in shear due to point spread function leakage and modelling error, and potentially provide improved precision in shear inference in high-resolution space-based images.
Moduli stabilization in finite modular symmetric models
Authors: Abe Yoshihiko , Goto Komei , Higaki Tetsutaro , Kobayashi Tatsuo , Nasu Kaito
Published: January 2025

We study vacua of moduli potential consisting of multiple contribution of modular forms in a finite modular symmetry. If the potential is given by a single modular form, the Minkowski vacuum is realized at the fixed point of the modular symmetry. We show that the de Sitter vacuum is realized with a multiple modular form case and obtain a non-trivial vacuum which is away from the fixed point, i.e. a large modulus vacuum expectation value, depending on the choice of the weight and representation of the modular forms. We study these vacua numerically and analytically. It is also found that the vacua obtained in this paper preserve CP symmetry.
Nutritional carryover effects of the previous plane of nutrition of crossbred Angus steers affects freshwater intake, animal performance, and water and feed efficiency
Authors: da Silva Aghata Elins Moreira , Macias Franco Arturo , de Moura Felipe Henrique , Norris Aaron , Bangert Kelli Noelle , Bezerra Leilson Rocha , Mota Lucas Gimenez , Fonseca Mozart Alves
Published: January 2025

This study evaluated how the backgrounding diet can affect water intake, animal performance and water and feed efficiency of steers fed finishing diets based on grains or forages. Twenty-four crossbred Angus steers (298 ± 10.2 kg) were fed during backgrounding either a moderate (MP, n = 12; triticale hay only, 9.1%crude protein [CP], 1.07 Mcal/kg net energy available for maintenance [NEm], and 0.52 Mcal/kg net energy available for gain [NEg]) or high plane of nutrition (HP, n = 12; 85% alfalfa hay and 15% beardless wheat hay, 12.62%CP, 1.23 Mcal/kg NEm, and 0.66 Mcal/kg NEg) during the background phase (85 d). After this period, steers were assigned to two finishing phase groups containing half of the animals from each backgrounding diets. During the finishing phase, animals were fed either a forage-based (Alfalfa hay; CP: 20.8% DM, NEm: 1.47 Mcal/kg, NEg: 0.88 Mcal/kg) or a grain-based diet (80% whole corn and 20% wheat hay; CP: 10.6% DM, NEm: 1.96 Mcal/kg, NEg: 1.31 Mcal/kg). There was no interaction between the effects of the previous plane of nutrition [(moderate (MP) or high (HP)] and finishing diets (forage or grain-fed) on any of the variables studied (P > 0.05). Animals backgrounded on MP were lighter and had a lower DMI when compared with HP (P < 0.01). However, no differences were observed on the drinking water intake (DWI) between MP and HP (P > 0.05). HP animals were more efficient in gross water efficiency (P < 0.01), but less efficient on residual feed intake (P < 0.05), compared to MP animals. During the finishing phase, forage fed animals had a greater DMI and DWI compared with grain-fed animals (P < 0.01), however, no differences were observed on the final BW (P > 0.05). Grain-fed animals were more efficient for water and feed intake and had a greater marbling score (P < 0.01) compared to forage-fed. Animals fed on HP and finished in a grain-fed diet had the least DWI (P < 0.05) and greatest body condition score (P < 0.05), marbling score (P < 0.01) and rib depth (P < 0.05). In the first 20 d of the finishing period, the previous plane affected the variables ADG, DMI, CPi, and DWI (as kg DMI and CP) in the finishing plane. Altogether, our results highlight the individual effects of backgrounding and finishing systems on DWI and the efficiency of finishing animals, as well as the importance of providing adequate nutrition during the earlier stages of life.
Safety evaluation for bogie with side bearer pad based on US CFR standard
Authors: Zhang Haifeng , Xu Yugong , Zhang Wenkang , Xue Shihai , Liu Xiong , Fang Xueqiao
Published: January 2025

Side bearer pad is a typical structure widely adopted in the design of the bogie supporting the subway vehicles in US. This type of bogie should meet the Code of Federal Regulations (CFR), so the safety of this type of bogie needs to be evaluated, especially the safety against derailment. Usually, the lateral and vertical force will be calculated from dynamics model by VAMPIRE or SIMPACK and the result compared with the Nadal limit to evaluate the derailment safety margin. Track condition, guard rail condition, wheel/rail CoF, side bearer pad CoF, speed are the major factors which affect the L/V. This paper will introduce the structure of bogie with side bearer pad and discuss the safety against derailment evaluation based on the sensitivity of the above factors.