bluuebunny/crossref_metadata_2025 huggingface dataset:
An “opinion reproduction number” for infodemics in a bounded-confidence content-spreading process on networks
Authors: Brooks Heather Z. , Porter Mason A.
Published: January 2025

We study the spreading dynamics of content on networks. To do this, we use a model in which content spreads through a bounded-confidence mechanism. In a bounded-confidence model (BCM) of opinion dynamics, the agents of a network have continuous-valued opinions, which they adjust when they interact with agents whose opinions are sufficiently close to theirs. Our content-spreading model, which one can also interpret as an independent-cascade model, introduces a twist into BCMs by using bounded confidence for the content spread itself. We define an analog of the basic reproduction number from disease dynamics that we call an opinion reproduction number. A critical value of the opinion reproduction number indicates whether or not there is an “infodemic” (i.e., a large content-spreading cascade) of content that reflects a particular opinion. By determining this critical value, one can determine whether or not an opinion dies off or propagates widely as a cascade in a population of agents. Using configuration-model networks, we quantify the size and shape of content dissemination by calculating a variety of summary statistics, and we illustrate how network structure and spreading-model parameters affect these statistics. We find that content spreads most widely when agents have a large expected mean degree or a large receptiveness to content. When the spreading process slightly exceeds the infodemic threshold, there can be longer dissemination trees than for larger expected mean degrees or receptiveness (which both promote content sharing and hence help push content spread past the infodemic threshold), even though the total number of content shares is smaller.
Force profile and charge estimation of a single particle in the sheath of a dual-frequency CCP
Authors: Niemann J. , Schneider V. , Kersten H.
Published: January 2025

This study presents a detailed investigation of the force profiles on optically trapped microparticles within the sheath of a dual-frequency capacitively coupled plasma, utilizing the particles as diagnostic probes. By systematically varying the phase angle between the applied frequencies (13.56 MHz and 27.12 MHz), the force profiles were precisely measured, revealing a strong dependence on the phase angle. Sheath parameters, including the position of the sheath edge and the location and magnitude of the electric field force maximum, were determined and found to correlate closely with the phase angle, similar to the dc self-bias. Various electric field models, including those derived from the matrix sheath theory and the Child–Langmuir law, were utilized to estimate the particle charge evolution within the sheath. The models were compared with the simulation results to evaluate their accuracy, revealing good agreement between simulations and analytic models. Differences were observed between the models in terms of both particle charge distribution and their absolute values. Averaging of the particle charges across the sheath revealed a significant dependence on the phase angle. Additionally, an independent approach was used to estimate the averaged particle charge by calculating the mechanical work required to move the particle through the sheath, which does not rely on any specific assumptions about the electric field. This consideration provided a benchmark for evaluating the different electric field models and offered insights into their relative accuracy.
Impaired spatial coding of the hippocampus in a dentate gyrus hypoplasia mouse model
Authors: Chen Xiaojing , Cheng Ning , Wang Cheng , Knierim James J.
Published: January 2025

The hippocampal dentate gyrus (DG) is thought to orthogonalize inputs from the entorhinal cortex (pattern separation) and relay this information to the CA3 region. In turn, attractor dynamics in CA3 perform a pattern completion or error correction operation before sending its output to CA1. In a mouse model of congenital hypoplasia of the DG, a deficiency in the
Wntless
(Wls) gene, specifically in cells expressing
Gfap-Cre
, which targets neuronal progenitors, led to an almost total absence of dentate granule cells and modestly impaired performance in spatial tasks. Here, we investigated the physiological consequences of granule cell loss in these mice by conducting in vivo calcium imaging from CA1 principal cells during behavior. The spatial selectivity of these cells was preserved without the DG. On a linear track, place fields in mutant mice were more likely to be near track terminals and to encode the distance from the start point in each running direction. In an open box, CA1 cells in mutant mice exhibited reductions in the percentage of place cells, in spatial information, and in place field stability. The reduction in place field stability across repeated exposures to the same environment resulted in a reduction in the differential representations of two different contexts in mutant mice compared to wild-type mice. These results suggest that DG helps to stabilize CA1 spatial representations, especially in 2-D environments, and that the lack of stability across similar environments may play a key role in the deficits of animals with DG dysfunction in discriminating different environments.
Comments on ‘Combined static and sliding friction on an inclined plane’
Authors: Kwang-Hua Chu A , Liu Shengjun
Published: January 2025

We make some crucial remarks about the recent presentation by Cross [Eur. J. Phys. 44 (2023) 055 006] for pedagogical purposes considering the above mentioned results. Most of the statements relevant to figure 2 of the above mentioned paper are of doubt to us. Our proposed amendments or corrections are useful for researchers as well as undergraduate physics students.
Interface trap dynamics and thermal effects in novel junctionless dual gate inverted-U-shaped FinFETs for sub-5 nm node: device to circuit level implementation
Authors: Bandi Bhanu Prakash , Sornapudi Uday Sankar Srinivas , Valasa Sresta , Kotha Venkata Ramakrishna , Bhukya Sunitha , Mudidhe Praveen Kumar , Tayal Shubham , Vadthiya Narendar
Published: January 2025

In this manuscript, for the first time, we explore the influence of interface trap charges (ITCs) on the novel junctionless dual gate inverted U-shaped FinFET device targeting the sub-5 nm technology node. The study mainly explores: (a) influence of acceptor and donor ITCs; (b) influence of temperature effects; (c) combined effects of temperature (250–350 K) and ITCs concentration variation (2 × 1012 cm−2–8 × 1012 cm−2); (d) design of single stage common source (CS) amplifier for analog IC applications. It is noticed that the presence of acceptor traps improves the digital and RF performance at higher V
GS, whereas donor traps enhance the analog performance of the designed device. An improvement (reduction) of ∼12.09% (∼17.33%) in I
ON is noticed for donor (acceptor) traps. the I
ON/I
OFF ratio is noticed to be improved (∼1011) for acceptor traps in comparison with donor traps (∼107) and no traps (∼109). The analog/RF figure of merits for temperature and ITCs variations is extracted at 100 nA µm−1 to target the low power applications. It is noticed that lowering the temperatures for the designed device is not suggestable for analog/RF performance as it degrades the device performance except for A
V whereas well suitable to improve the digital performance. Moreover, increasing the acceptor and donor trap concentrations degraded both the digital, and analog/RF metrics of the device. Further, the CS amplifier produced near equal gains for no trap, acceptor trap, and donor traps indicating that the CS amplifier circuit is resilient to traps and adopted into analog IC applications.
Plasma-activated liquid mediated sensitization of cisplatin in chemoresistant ovarian cancer by disrupting DNA damage response
Authors: Jinren Liu , Xiangni Wang , Yixin Cui , Guimin Xu , Jiajia Lu , Zhirou He , Yulin Xu , Rongrong Li , Lingge Gao , Hong Wang , Junhong Gao , Xili Wu , Xingmin Shi , Guanjun Zhang
Published: January 2025

Cisplatin resistance coupled with adverse effects presents substantial hurdles in the treatment of ovarian cancer. Both cold atmospheric plasma and plasma-activated liquid (PAL) hold the ability to induce DNA damage, which is a primary target of cisplatin. In this study, we investigate the potential of PAL in augmenting cisplatin sensitivity or diminishing the necessary drug dosage by impairing the DNA of cisplatin-resistant cancer cells. We found that plasma irradiated medium exceeding 40 s could decrease the viability, induce DNA damage, trigger cell cycle arrest, and augment apoptosis and autophagy in two types of cisplatin-resistant ovarian cancer cells (A2780/DDP and SKOV3/DDP) after a 24 h incubation period. Notably, pre-treatment with 40 s plasma-activated medium (PAM) for 2 h significantly enhanced the anti-cancer effect of cisplatin administered at lower doses on these cell types. RNA-seq, quantitative real-time PCR and Western blotting analysis revealed that PAM treatment could downregulate the expression of several pivotal proteins involved in nucleotide excision repair (NER) and homologous recombination repair (HRR). The mouse xenograft tumor model demonstrated that plasma-activated saline and cisplatin synergistically inhibited tumor growth and significantly suppressed the expression of proteins related to HRR and NER pathways. We identified plasma-derived peroxide generation in PAM as crucial in these processes. These results pave the way for considering PAM as an adjuvant treatment for cisplatin-resistant ovarian cancer and other abdominal cancers. Additionally, the findings indicate the feasibility of reducing cisplatin dosage to alleviate side effects through sensitization.
Causality enhanced deep learning framework for quality characteristic prediction via long sequence multivariate time-series data
Authors: Cui Qing’an , Lu Jiao , Yin Xianhui
Published: January 2025

Prediction of product quality characteristics plays an important role in the timely identification of quality conditions and in triggering an alarm for abnormal products. In modern manufacturing, the large number of parameters collected by sensors and complex interactions between operational parameters have led to complexity and difficulty in quality monitoring during the production process. To minimize noise interference, reduce modeling complexity, and improve prediction accuracy and interpretability, this study proposes a time-series causal discovery and quality prediction framework for multistage manufacturing processes. Initially, a hierarchical Peter–Clark momentary conditional independence algorithm with multiple time-lag detection accuracy algorithm was proposed. It is designed to identify optimal time lags, establish causal relationships between process parameters and quality characteristics, and efficiently extract the root process parameters. Furthermore, a temporal pattern attention–long short-term memory model is employed to predict the quality characteristics for multivariate time series data, and is aided by the obtained causal structure. Finally, data obtained through a simulation and a case study involving a multistage continuous production chemical process are utilized to verify the performance and superiority of the proposed method.
Weak signal propagation: an optimal amplification induced by intra-layer coupling in a Y-shaped unidirectional chain
Authors: Wu Liqing , Cheng Shanshan , Zheng Yage , Yi Ming , Wei Zhouchao , Lu Lulu
Published: January 2025

Weak signal amplification is extremely important in biological systems (such as brain, nerve cells, gene regulatory networks), which relates to signal coding and processing. This study incorporates intra-layer coupling within a simple Y-shaped unidirectional chain as a means of exploring the effect of small changes in the network structure on the propagation of weak signals, where the nodes in the chain are treated as bistable oscillators. It is found that when the intra-layer coupling is below a critical threshold and the inter-layer coupling is at a medium range, the transmission of signals in the initial layer is significantly enhanced. This study also reveals the amplification mechanism of weak signals in the Y-shaped unidirectional chain. The successful amplification of weak signals in the Y-shaped unidirectional chain is related to the synchronization state of the feed-forward oscillators and the amplitude of oscillators. The signal amplification is also determined by the frequency of the input signals. Furthermore, this paper has contrasted numerical simulations with analytical calculations in this simplified topology. This research contributes to understanding the relationship between network structure and weak signal transmission.
Performance-based reliability modelling of displacement control system considering the internal degradation and external impacts
Authors: Geng Yixuan , Wang Shaoping , Wang Weijie , Chen Rentong , Zhang Chao
Published: January 2025

It is still a challenge to evaluate the reliability of displacement control systems (DCS), which are widely used in extreme scenarios with multi-component degradation, external shock impacts, measurement noise and disturbances, and have closed-loop self-compensating capability. This paper proposes a performance-based reliability model for DCS, which considers the challenges above to ensure the safe application of DCS within a certain fault-tolerant range. Specifically, the coupled relationship between degradation and shock is characterized by the energy-related additional degradation amount, and the effects of sensor measurement error and external environmental disturbance on the system performance are taken into consideration. A nonlinear hybrid model of DCS is established by integrating the cumulative degradation amount as an extended state variable; then, based on the control performance, a reliability index is defined and a general performance-based reliability evaluation method is proposed. The method is validated through a case study on a hydraulic servo control system, demonstrating its ability to accurately describe the performance changes of DCS under various degradation interactions, to provide compensation capability analysis and to more accurate reliability evaluation.
Advances and prospects for whispering gallery mode microcavities in quantum precision measurement applications
Authors: Zhang Lingwei , Zhou Xinxiu , Shang Jingcheng , Jiang Pei , Zhai Yueyang , Liu Gang
Published: January 2025

Large volumes of light sources and their characteristics control devices are challenges to out-of-laboratory applications of quantum precision measurement devices, such as spin-exchange relaxation-free (SERF) inertial and extremely weak magnetic field measurement devices. High-Q whispering gallery mode (WGM) resonators have excellent optical field confinement capability, extremely narrow linewidth, and small mode volume, which can easily realize compact low noise and high-frequency stability light sources, having a great potential to realize more compact quantum precision measurement devices. This will broaden the use of quantum precision measurement devices in areas such as transportable SERF gyroscopes, wearable magnetometers, etc. In this review, the fundamentals and characteristics of WGM optical cavities are firstly introduced, as well as its fabrication techniques and built-up materials. Then, the laser stabilizing applications of WGM optical cavities including wavelength tuning, self-injection locking, and thermal stabilization are discussed. Finally, the application prospects of quantum precision measurement are discussed.
Accessing the accuracy of full-field crystal plasticity models using in situ high energy x-ray diffraction microscopy
Authors: Zhang Sheng , Diehl Martin , Maldar Alireza , Shang Xiaoqing , Zeng Xiaoqin , Wang Leyun
Published: January 2025

Abstract

Crystal Plasticity (CP) modeling is well-known for the accurate prediction of averaged quantities such as the stress–strain response and the evolution of crystallographic texture. It is, however, less established to which extent full-field CP models can correctly predict the local deformation behavior at grain scale. In this study, the capabilities of CP models in predicting the local behavior are assessed by experimental results from a tensile test of a Mg-3Y(Wt.%) polycrystal characterized in situ by far-field high energy x-ray diffraction microscopy. To this end, the deformation of 955 grains near the Gauge center was simulated using a fast Fourier transformation based CP framework. From undeformed state to elasto-plastic transition stage, the simulation reasonably forecasts the stress–strain response of individual grains while the crystallographic re-orientations are not correctly predicted. Small discrepancies in type III stress tensors, which lead to the activation of different slip systems, are identified as one important reason. Possible sources for the discrepancy between simulated and experimental type III stress tensors are discussed.
Hybrid combination of advanced oxidation process with membrane technology for wastewater treatment: gains and problems
Authors: Regmi Chhabilal , Kshetri Yuwaraj K , Wickramasinghe S Ranil
Published: January 2025

Over the past few decades, significant efforts have been dedicated to advancing technologies for the removal of micropollutants from water. Achieving complete pure water with a single treatment process is challenging and nearly impossible. One promising approach among various alternatives is adopting hybrid technology, which is considered as a win–win technology. It utilizes the advantages of each technique, resulting in the enhancement of wastewater treatment. This pioneering idea is designed to significantly enhance water quality, addressing real-world implementation hurdles, and offer a promising solution to the worldwide issue of water scarcity. This review assesses the merits and drawbacks of the hybrid photocatalytic membrane technology employed in wastewater treatment. Notably, this hybrid process not only improves the membrane filtration capacity and permeates water quality but also enhances the antifouling performance of the membrane. However, it is crucial to acknowledge potential drawbacks, such as membrane structure degradation and photocatalytic activity loss in nanoparticles during the operation period. While improvements in wastewater treatment efficiency are evident, there remains ample room for further enhancements. The review summarizes the future directions and challenges of implementing such an integrated system.
Ion confinement and temperature in minimum-B electron cyclotron resonance ion source plasmas
Authors: Tarvainen O , Toivanen V , Timonen O , Kronholm R , Koivisto H
Published: January 2025

We review the current understanding of high charge state ion confinement and ion temperature in Electron Cyclotron Resonance Ion Sources (ECRIS). Experiments probing the ion confinement time of various charge states strongly favour a confinement scheme where the high charge state ions are trapped in a local dip of the ambipolar plasma potential. The electrostatic confinement permits ion confinement times of 10 ms order-of-magnitude. The dwelling time of the ions, undergoing stepwise ionisation from neutrals to high charge states, is long enough for the energy transfer from the plasma electrons to heat the ions to 10–15 eV while the energy exchange in ion–ion collisions results in all charge states having essentially the same temperature. We then describe a technique, using the ion temperatures obtained through optical emission spectroscopy and afterglow transient beam currents, to estimate the magnitude of the potential dip. In our example, measured with a 14 GHz ECRIS the value of the potential dip is 1.3–1.9 V. We demonstrate that the temporal characteristics of the afterglow transient occurring in 1 ms scale can be estimated by assuming that the afterglow peak of high charge state ion currents is caused by a change of the ion confinement scheme from electrostatic trapping to random walk diffusion resulting in order-of-magnitude reduction of the ion confinement time.
Perturbative framework for engineering arbitrary Floquet Hamiltonian
Authors: Xu Yingdan , Guo Lingzhen
Published: January 2025

We develop a systematic perturbative framework to engineer an arbitrary target Hamiltonian in the Floquet phase space of a periodically driven oscillator based on Floquet–Magnus expansion. The high-order errors in the engineered Floquet Hamiltonian are mitigated by adding high-order driving potentials perturbatively. We introduce a transformation method that allows us to obtain an analytical expression of the leading-order correction drive for engineering a target Hamiltonian with discrete rotational and chiral symmetries in phase space. We also provide a numerically efficient procedure to calculate high-order correction drives and apply it to engineer the target Hamiltonian with degenerate eigenstates of multi-component cat states that are important for fault-tolerant hardware-efficiency bosonic quantum computation.
Displacement and force transmissibility of a quasi-zero-stiffness-based compliant metamaterial structure
Authors: Banerjee Payal , Balaji P S , Leblouba Moussa , Murugan S
Published: January 2025

It is critical to minimize vibration interference in sensitive engineering systems. A vibration isolator improves system performance and durability by reducing the transmission of vibrations between objects. However, achieving effective isolation at low frequencies with traditional linear isolators requires large static deflection, limiting their performance. Nonlinear isolators offer a solution by providing low dynamic stiffness while maintaining a high load-bearing capacity, achieving quasi-zero stiffness (QZS) characteristics. This study presents a compliant QZS (CQZS) metamaterial structure for low-frequency vibration isolation. The CQZS metastructure was designed, 3D printed, and subjected to static and dynamic analysis. Harmonic balance methods were applied to model the system, and experiments on displacement and force transmissibility validated the design’s effectiveness. The results showed that the CQZS structure achieves a QZS region of 10 mm and effective isolation at 4.5 Hz. The design is simpler, lighter and more manufacturable than conventional QZS structures.
Thermal characterization, modeling and parametric model order reduction (PMOR) of piezoelectric transducers
Authors: Ratke Xenia Y , Sattel Thomas
Published: January 2025

The consideration of the thermals of piezoelectric transducers has gained relevance due to the increasing demands on the performance of actuators as well as the special applications such as high-power, high-precision or high-temperature applications. In the state of the art, many works deal with the representation of the temperature-dependence of piezoelectric performance and the development of suitable systems that are optimized in terms of self-heating. The prerequisite for this, is to characterize the actuators thermally and to have thermal models of piezoelectric actuators, that represent the temperature of the actuator. In this paper a workflow is presented for the thermal characterization and modeling of piezoelectric transducers in a fast and non-destructive manner. Aim of this work is to generate Finite-Element (FE) Models and Reduced Order Models (ROM) of the thermal behavior of piezoelectric transducers for many different sizes of actuators. For this purpose an experimental setup and characterization workflow are developed. The advantage of the workflow lies in the speed of characterization through direct comparison of measurement results with a Metamodel and automated model order reduction. Parametric model order reduction is also investigated in this context for faster model building and compared to the results of FE and ROM. Model order reduction offers the advantage that the resulting models are low in computing effort, can be used without FE software and can directly be included in for example control or system models. Finally by direct comparison with a simple circuit model as in the state of the art the advantages of FE modeling can be shown. The workflow can be used for many different test specimen that vary in size and shape. The method is exemplarily presented using a Lead Zirconate Titanate (PZT) multilayer actuator.
Annealing temperatures effects on structural and optical properties of CdO thin films
Authors: Aydin Handan , Odak Mehmet
Published: January 2025

In this study, the structural and optical properties of CdO thin films subjected to heat treatment at different temperatures were investigated. CdO films were deposited on glass substrates by thermal evaporation. X-ray diffraction technique (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and atomic force microscopy (AFM) measurements were taken to investigate the crystal structure and surface morphology of the prepared films UV–vis spectrometer was utilized to measure the optical properties. As a result of XRD measurements, it was observed that the CdO thin film without and with heat treatment has a cubic crystal structure. The increase in the sharpness of x-ray peaks in CdO thin films with heat treatment means an increase in crystallization, and the calculated crystal sizes showed that the crystal size generally tends to increase with a rise in the applied annealing temperature. As can be seen from the SEM images, it was observed that the small grains on the surface were replaced by large grains as a result of the merger of small grains with each other with rising annealing temperature. The optical band gap Eg, which changes with heat treatment, was calculated to be between 2.45 and 2.27 eV. It was concluded that heat treatment improves the conductivity of CdO thin films by reducing the Eg value.
Investigation on tunable red and white emissions in Bi3+/Eu3+ co-doped Y2Zr2O7 microcrystals
Authors: Zuo Ruiliang , Zhang Zehua , Liang Jingheng , Jiang Zhenzhen , Wang Lili , Tiu Zian Cheak
Published: January 2025

In this study, we synthesized Y2Zr2O7 (YZO): Bi3+/Eu3+ microcrystals through high-temperature solid-phase method. When the microcrystals were excited upon 263 nm and 329 nm, a tunable emission color variation from red to white is observed. The Correlated Color Temperature (CCT) of YZO: 6% mol Bi3+, 5% mol Eu3+ excited upon 329 nm is 4194 K, exhibited warm white light. Furthermore, the emission intensity of Eu3+ ion is remarkably improved by the incorporation of Bi3+ ion, due to the energy transfer from Bi3+ ion to Eu3+ ion. Their efficiency (η
T) in YZO: 6% mol Bi3+, 5% mol Eu3+ reaches 49.17%. The corresponding absolute quantum efficiency (λ
ex = 329 nm) of YZO: 6% mol Bi3+, 5% mol Eu3+ is 56.21%. These results indicate that YZO: Bi3+/Eu3+ microcrystals are highly potential to enhance the industrial growth of photonics field, particularly the application of anti-counterfeiting and white light-emitting diodes.
DESI2024: Dark Energy Spectroscopic Instrument (DESI) survey, presentation of Year 1 results
Authors: Dawson Kyle , Palanque-Delabrouille Nathalie
Published: January 2025

The series of papers included in this special issue represent the first cosmological measurements from the Dark Energy Spectroscopic Instrument (DESI). These papers present the validation of the DESI clustering catalogs, the methodology for the cosmology measurements, and the full cosmology implications. These measurements were derived from a catalog of approximately 6.4 million extragalactic sources in a redshift range of 0.1 < z < 4.2. Owing to advances in fiber positioner technology and to a larger telescope, this sample was acquired in only one year of observation, yet is more than double the size of the galaxy and quasar samples from the first four phases of the Sloan Digital Sky Survey (SDSS) that spanned 20 years. With these new galaxy and quasar catalogs, the DESI collaboration completed percent-level constraints on the cosmic expansion history and the growth of structure. In turn, these new measurements provided a new platform from which to test the equation of state of dark energy, the summed mass of the three neutrino mass eigenstates, global curvature, and General Relativity. By surpassing the precision of the previous generation spectroscopic survey, the results in this special issue mark the transition in the field of cosmology to Stage-IV dark energy science.
Production of alternate realizations of DESI fiber assignment for unbiased clustering measurement in data and simulations
Authors: Lasker J. , Carnero Rosell A. , Myers A.D. , Ross A.J. , Bianchi D. , Hanif M.M.S. , Kehoe R. , de Mattia A. , Napolitano L. , Percival W.J. , Staten R. , Aguilar J. , Ahlen S. , Bigwood L. , Brooks D. , Claybaugh T. , Cole S. , de la Macorra A. , Ding Z. , Doel P. , Fanning K. , Forero-Romero J.E. , Gaztañaga E. , Gontcho S.Gontcho A. , Gutierrez G. , Honscheid K. , Howlett C. , Juneau S. , Kremin A. , Landriau M. , Le Guillou L. , Levi M.E. , Manera M. , Meisner A. , Miquel R. , Moustakas J. , Mueller E. , Nie J. , Niz G. , Oh M. , Palanque-Delabrouille N. , Poppett C. , Prada F. , Rezaie M. , Rossi G. , Sanchez E. , Schlegel D. , Schubnell M. , Seo H. , Sprayberry D. , Tarlé G. , Vargas-Magaña M. , Weaver B.A. , Wilson Michael J. , Zheng Y. ,   The DESI collaboration
Published: January 2025

A critical requirement of spectroscopic large scale structure analyses is correcting for selection of which galaxies to observe from an isotropic target list. This selection is often limited by the hardware used to perform the survey which will impose angular constraints of simultaneously observable targets, requiring multiple passes to observe all of them. In SDSS this manifested solely as the collision of physical fibers and plugs placed in plates. In DESI, there is the additional constraint of the robotic positioner which controls each fiber being limited to a finite patrol radius. A number of approximate methods have previously been proposed to correct the galaxy clustering statistics for these effects, but these generally fail on small scales. To accurately correct the clustering we need to upweight pairs of galaxies based on the inverse probability that those pairs would be observed (Bianchi & Percival 2017). This paper details an implementation of that method to correct the Dark Energy Spectroscopic Instrument (DESI) survey for incompleteness. To calculate the required probabilities, we need a set of alternate realizations of DESI where we vary the relative priority of otherwise identical targets. These realizations take the form of alternate Merged Target Ledgers (AMTL), the files that link DESI observations and targets. We present the method used to generate these alternate realizations and how they are tracked forward in time using the real observational record and hardware status, propagating the survey as though the alternate orderings had been adopted. We detail the first applications of this method to the DESI One-Percent Survey (SV3) and the DESI year 1 data. We include evaluations of the pipeline outputs, estimation of survey completeness from this and other methods, and validation of the method using mock galaxy catalogs.
Impact of systematic redshift errors on the cross-correlation of the Lyman-α forest with quasars at small scales using DESI Early Data
Authors: Bault Abby , Kirkby David , Guy Julien , Brodzeller Allyson , Aguilar J. , Ahlen S. , Bailey S. , Brooks D. , Cabayol-Garcia L. , Chaves-Montero J. , Claybaugh T. , Cuceu A. , Dawson K. , de la Cruz R. , de la Macorra A. , Dey A. , Doel P. , Filbert S. , Font-Ribera A. , Forero-Romero J.E. , Gaztañaga E. , Gontcho S.Gontcho A. , Gordon C. , Herrera-Alcantar H.K. , Honscheid K. , Iršič V. , Karaçaylı N.G. , Kehoe R. , Kisner T. , Kremin A. , Lambert A. , Landriau M. , Le Guillou L. , Levi M.E. , Manera M. , Martini P. , Meisner A. , Miquel R. , Montero-Camacho P. , Moustakas J. , Muñoz-Gutiérrez A. , Nie J. , Niz G. , Palanque-Delabrouille N. , Percival W.J. , Pérez-Ràfols I. , Poppett C. , Prada F. , Ramírez-Pérez C. , Ravoux C. , Rezaie M. , Rossi G. , Sanchez E. , Schlafly E.F. , Schlegel D. , Schubnell M. , Silber J. , Tan T. , Tarlé G. , Walther M. , Weaver B.A. , Zhou Z.
Published: January 2025

The Dark Energy Spectroscopic Instrument (DESI) will measure millions of quasar spectra by the end of its 5 year survey. Quasar redshift errors impact the shape of the Lyman-α forest correlation functions, which can affect cosmological analyses and therefore cosmological interpretations. Using data from the DESI Early Data Release and the first two months of the main survey, we measure the systematic redshift error from an offset in the cross-correlation of the Lyman-α forest with quasars. We find evidence for a redshift dependent bias causing redshifts to be underestimated with increasing redshift, stemming from improper modeling of the Lyman-α optical depth in the templates used for redshift estimation. New templates were derived for the DESI Year 1 quasar sample at z > 1.6 and we found the redshift dependent bias, Δr
∥, increased from -1.94 ± 0.15 h
-1 Mpc to -0.08 ± 0.04 h
-1 Mpc (-205 ± 15 km s-1 to -9.0 ± 4.0 km s-1). These new templates will be used to provide redshifts for the DESI Year 1 quasar sample.
Suppressing the sample variance of DESI-like galaxy clustering with fast simulations
Authors: Ding Z. , Variu A. , Alam S. , Yu Y. , Chuang C. , Paillas E. , Garcia-Quintero C. , Chen X. , Mena-Fernández J. , Aguilar J. , Ahlen S. , Brooks D. , Claybaugh T. , de la Macorra A. , Doel P. , Fanning K. , Forero-Romero J.E. , Gaztañaga E. , Gontcho S.Gontcho A. , Gutierrez G. , Hahn C. , Honscheid K. , Howlett C. , Juneau S. , Kehoe R. , Kisner T. , Kremin A. , Lambert A. , Landriau M. , Le Guillou L. , Manera M. , Miquel R. , Mueller E. , Myers A.D. , Nie J. , Niz G. , Poppett C. , Rezaie M. , Rossi G. , Sanchez E. , Schubnell M. , Seo H. , Silber J. , Sprayberry D. , Tarlé G. , Vargas-Magaña M. , Zou H.
Published: January 2025

Ongoing and upcoming galaxy redshift surveys, such as the Dark Energy Spectroscopic Instrument (DESI) survey, will observe vast regions of sky and a wide range of redshifts. In order to model the observations and address various systematic uncertainties, N-body simulations are routinely adopted, however, the number of large simulations with sufficiently high mass resolution is usually limited by available computing time. Therefore, achieving a simulation volume with the effective statistical errors significantly smaller than those of the observations becomes prohibitively expensive. In this study, we apply the Convergence Acceleration by Regression and Pooling (CARPool) method to mitigate the sample variance of the DESI-like galaxy clustering in the AbacusSummit simulations, with the assistance of the quasi-N-body simulations FastPM.
Based on the halo occupation distribution (HOD) models, we construct different FastPM galaxy catalogs, including the luminous red galaxies (LRGs), emission line galaxies (ELGs), and quasars, with their number densities and two-point clustering statistics well matched to those of AbacusSummit.
We also employ the same initial conditions between AbacusSummit and FastPM to achieve high cross-correlation, as it is useful in effectively suppressing the variance.
Our method of reducing noise in clustering is equivalent to performing a simulation with volume larger by a factor of 5 and 4 for LRGs and ELGs, respectively.
We also mitigate the standard deviation of the LRG bispectrum with the triangular configurations k
2 = 2k
1 = 0.2 h Mpc-1 by a factor of 1.6.
With smaller sample variance on galaxy clustering, we are able to constrain the
baryon acoustic oscillations (BAO)
scale parameters to higher precision. The CARPool method will be beneficial to better constrain the theoretical systematics of BAO, redshift space distortions (RSD) and primordial
non-Gaussianity (NG).
Impact and mitigation of spectroscopic systematics on DESI DR1 clustering measurements
Authors: Krolewski A. , Yu J. , Ross A.J. , Penmetsa S. , Percival W.J. , Zhou R. , Wilson M.J. , Hou J. , Aguilar J. , Ahlen S. , Brooks D. , Chaussidon E. , Claybaugh T. , de la Macorra A. , Dey Biprateep , Forero-Romero J.E. , Gontcho S.Gontcho A. , Guy J. , Honscheid K. , Juneau S. , Kirkby D. , Kisner T. , Kremin A. , Lambert A. , Le Guillou L. , Levi M.E. , Martini P. , Meisner A. , Miquel R. , Moustakas J. , Myers A.D. , Newman J.A. , Niz G. , Palanque-Delabrouille N. , Rossi G. , Sanchez E. , Schlafly E.F. , Schlegel D. , Schubnell M. , Seo H. , Sprayberry D. , Tarlé G. , Weaver B.A. , Zhao C.
Published: January 2025

The large scale structure catalogs within DESI Data Release 1 (DR1) use nearly 6 million galaxies and quasars as tracers of the large-scale structure of the universe to measure the expansion history with baryon acoustic oscillations and the growth of structure with redshift-space distortions.
In order to take advantage of DESI's unprecedented statistical power, we must ensure that the galaxy clustering measurements are unaffected by non-cosmological density fluctuations.
One source of spurious fluctuations comes from
variation in galaxy density with spectroscopic observing conditions, lowering the redshift efficiency (and thus galaxy density) in certain areas of the sky.
We measure the uniformity of the redshift success
rate for DESI luminous red galaxies (LRG), bright galaxies (BGS) and quasars (QSO), complementing the detailed discussion of emission line galaxy (ELG) systematics in a companion paper [1].
We find small but significant fluctuations of up to 3% in redshift success rate with the effective spectroscopic signal-to-noise, and create and describe weights that remove these fluctuations.
We also describe the process to identify and remove data from certain poorly performing fibers from DESI DR1, and measure the stability of the redshift success rate with time.
Finally, we find small but significant correlations
of redshift success rate with position on the focal plane, survey speed, and number of exposures required, and show the impact of weights correcting these trends on the power spectrum multipoles and on cosmological parameters from BAO and RSD fits.
These corrections change the best-fit parameters by <15% of their statistical errors, and thus contribute negligibly to the overall DESI error budget.
Validation of the DESI 2024 Lyα forest BAO analysis using synthetic datasets
Authors: Cuceu Andrei , Herrera-Alcantar Hiram K. , Gordon Calum , Martini Paul , Guy Julien , Font-Ribera Andreu , Gonzalez-Morales Alma X. , Abdul Karim M. , Aguilar J. , Ahlen S. , Armengaud E. , Bault A. , Brooks D. , Claybaugh T. , de la Macorra A. , Doel P. , Fanning K. , Ferraro S. , Forero-Romero J.E. , Gaztañaga E. , Gontcho S.Gontcho A. , Gutierrez G. , Honscheid K. , Howlett C. , Karaçaylı N.G. , Kirkby D. , Kremin A. , Landriau M. , Le Goff J.M. , Le Guillou L. , Levi M.E. , Manera M. , Meisner A. , Miquel R. , Moustakas J. , Muñoz-Gutiérrez A. , Myers A.D. , Niz G. , Palanque-Delabrouille N. , Percival W.J. , Poppett C. , Prada F. , Pérez-Ràfols I. , Ramírez-Pérez C. , Ravoux C. , Rezaie M. , Rossi G. , Sanchez E. , Schlegel D. , Schubnell M. , Seo H. , Sprayberry D. , Tan T. , Tarlé G. , Vargas-Magaña M. , Walther M. , Weaver B.A. , Zhou R. , Zou H.
Published: January 2025

The first year of data from the Dark Energy Spectroscopic Instrument (DESI) contains the largest set of Lyman-α (Lyα) forest spectra ever observed. This data, collected in the DESI Data Release 1 (DR1) sample, has been used to measure the Baryon Acoustic Oscillation (BAO) feature at redshift z = 2.33. In this work, we use a set of 150 synthetic realizations of DESI DR1 to validate the DESI 2024 Lyα forest BAO measurement presented in [1]. The synthetic data sets are based on Gaussian random fields using the log-normal approximation. We produce realistic synthetic DESI spectra that include all major contaminants affecting the Lyα forest. The synthetic data sets span a redshift range 1.8 < z < 3.8, and are analysed using the same framework and pipeline used for the DESI 2024 Lyα forest BAO measurement. To measure BAO, we use both the Lyα auto-correlation and its cross-correlation with quasar positions. We use the mean of correlation functions from the set of DESI DR1 realizations to show that our model is able to recover unbiased measurements of the BAO position. We also fit each mock individually and study the population of BAO fits in order to validate BAO uncertainties and test our method for estimating the covariance matrix of the Lyα forest correlation functions. Finally, we discuss the implications of our results and identify the needs for the next generation of Lyα forest synthetic data sets, with the top priority being to simulate the effect of BAO broadening due to non-linear evolution.
Enhancing transcranial ultrasound stimulation planning with MRI-derived skull masks: a comparative analysis with CT-based processing
Authors: Zadeh Ali K , Puonti Oula , Sigurðsson Björn , Thielscher Axel , Monchi Oury , Pichardo Samuel
Published: January 2025

Objective. Transcranial ultrasound stimulation (TUS) presents challenges in ultrasound wave transmission through the skull, affecting study outcomes due to aberration and attenuation. While planning strategies incorporating 3D computed tomography (CT) scans help mitigate these issues, they expose participants to radiation, which can raise ethical concerns. A solution involves generating skull masks from participants’ anatomical magnetic resonance imaging (MRI). This study aims to compare ultrasound field predictions between CT-derived and MRI-derived skull masks in TUS planning. Approach. Five participants with a range of skull density ratios (SDRs: 0.31, 0.42, 0.55, 0.67, and 0.79) were selected, each having both CT and T1/T2-weighted MRI scans. Ultrasound simulations were performed using BabelBrain software with a single-element transducer (diameter = 50 mm, F# = 1) at 250, 500, and 750 kHz frequencies. CT scans were used to generate maps of the skull’s acoustic properties. The MRI scans were processed using the Charm segmentation tool from the SimNIBS tool suite using default and custom settings adapted for better skull segmentation. Ultrasound was adjusted to target 30 mm below the skull’s surface at 54 electroencephalogram (EEG) locations. Main Results. The custom setting in Charm significantly improved the Dice coefficient between MRI- and CT-derived masks when compared to the default setting (p < 0.001). The maximum pressure error significantly decreased in the custom setting compared to the default setting (p < 0.001). Additionally, the focus location error median across different SDRs averaged 2.32, 1.45, and 1.57 mm in default and 2.08, 1.38, and 1.44 mm in custom conditions for 250 kHz, 500 kHz, and 750 kHz respectively. Significance. MRI-derived skull masks offer satisfactory accuracy at many EEG sites, and using custom settings can further enhance this accuracy. However, significant errors at specific locations highlight the importance of carefully considering stimulation location when choosing between CT- and MRI-derived skull modeling.
Diffusion transformer-augmented fMRI functional connectivity for enhanced autism spectrum disorder diagnosis
Authors: Zhao Haokai , Lou Haowei , Yao Lina , Zhang Yu
Published: January 2025

Objective. Functional magnetic resonance imaging (fMRI) is often modeled as networks of Regions of Interest and their functional connectivity to study brain functions and mental disorders. Limited fMRI data due to high acquisition costs hampers recognition model performance. We aim to address this issue using generative diffusion models for data augmentation. Approach. We propose Brain-Net-Diffusion, a transformer-based latent diffusion model to generate realistic functional connectivity for augmenting fMRI datasets and evaluate its impact on classification tasks. Main results. The Brain-Net-Diffusion effectively generates connectivity patterns resembling real data and significantly enhances classification performance. Augmentation using Brain-Net-Diffusion increased downstream autism spectrum disorder classification accuracy by 4.3% compared to no augmentation. It also outperformed other augmentation methods, with accuracy improvements ranging from 1.3% to 2.2%. Significance. Our approach demonstrates the effectiveness of diffusion models for fMRI data augmentation, providing a robust solution for overcoming data scarcity in functional connectivity analysis. To facilitate further research, we have made our code publicly available at https://github.com/JoeZhao527/brain-net-diffusion.
Efficient calculation of self magnetic field, self-force, and self-inductance for electromagnetic coils with rectangular cross-section
Authors: Landreman Matt , Hurwitz Siena , Antonsen Thomas M.
Published: January 2025

For designing high-field electromagnets, the Lorentz force on coils needs to be computed in order to design suitable support structures, and the inductance should be computed to evaluate the stored energy and dynamics. Also, the magnetic field and its variation inside the conductor is of interest for computing stress and strain, and due to superconducting quench limits. For these force, inductance, energy, and internal field calculations, the coils cannot be naively approximated as infinitesimally thin filaments due to divergences when the source and evaluation points coincide, so more computationally demanding calculations are usually required, resolving the finite cross-section of the conductors. Here, we present a new alternative method that enables the internal magnetic field vector, self-force, and self-inductance to be computed rapidly and accurately within a 1D filament model. The method is applicable to coils for which the curve center-line can have general noncircular shape, as long as the conductor width is small compared to the radius of curvature. This paper extends a previous calculation for circular-cross-section conductors (Hurwitz et al 2024 IEEE Trans. Magn.) to consider the case of rectangular cross-section. The reduced model is derived by rigorous analysis of the singularity, regularizing the filament integrals such that they match the true high-dimensional integrals at high coil aspect ratio. The new filament model exactly recovers analytic results for a circular coil, and is shown to accurately reproduce full finite-cross-section calculations for a non-planar coil of a stellarator magnetic fusion device. Due to the efficiency of the model here, it is well suited for use inside design optimization.
Cleopatra: a 12-channel recycling integrator ASIC for the
readout of hydrogenated amorphous silicon detectors in radiotherapy dosimetry
Authors: Mazza G. , Wheadon R. , Lenta F. , Buti C. , Fabi M. , Grimani C. , Pallotta S. , Sabbatini F. , Talamonti C. , Villani M. , Aziz S. , Calcagnile L. , Caricato A.P. , Martino M. , Maruccio G. , Monteduro A.G. , Quarta G. , Rizzato S. , Catalano R. , Cirrone G.A.P. , Cuttone G. , Guarrera M.C. , Petringa G. , Frontini L. , Liberali V. , Stabile A. , Vasquez M. , Croci T. , Ionica M. , Kanxheri K. , Menichelli M. , Morozzi A. , Moscatelli F. , Passeri D. , Pedio M. , Peverini F. , Placidi P. , Servoli L. , Tosti L. , Zema N. , Caputo D. , De Cesare G. , Lovecchio N. , Nascetti A. , Calvo D. , Cirio R. , De Remigis P. , Dunand S. , Thomet J.E. , Large M. , Petasecca M. , Bashiri A. , Piccolo L. , Wyrsch N. ,   the HASPIDE collaboration
Published: January 2025

The Cleopatra ASIC is a 12-channel prototype ASIC for the readout of hydrogenated
amorphous silicon sensors used for real-time dosimetry in radiation diagnostic and radiation
therapy. The architecture is based on a current to frequency conversion based on the recycling
integrator principle in order to cover a dynamic range of four orders of magnitude with high
linearity. Three different input amplifier configurations have been implemented in order to check
the trade-off between detector capacitance and maximum output frequency. Cleopatra has been
designed in CMOS 28 nm technology and succesfully tested in laboratory.