bluuebunny/crossref_metadata_2025_split huggingface dataset:
Statistical investigation of solar flares showing quasi-periodicity based on STIX quick-look light curves
Authors: Szaforz Ż. , Mrozek T. , Tomczak M. 
Published: January 2025

Context. The emission of radiation associated with the release of energy in solar flares is often modulated according to a quasi-oscillatory pattern. This behavior is known as quasi-periodic pulsation (QPP). In this work, the STIX instrument on board Solar Orbiter was used to study solar flares that show quasi-periodic variations in X-ray emission.
Aims. This work aimed to conduct a statistical study of the periods and amplitudes of QPPs observed in quick-look light curves of the STIX instrument.
Methods. The quick-look light curves recorded from April 14, 2020 (the beginning of the mission) to the end of March, 2022 were scrutinized. 129 flares with the most distinct pulses were selected, for which the periodicity analysis was carried out using the Lomb-Scargle periodogram and the autocorrelation method. This sample contained mostly weak B- and C-class flares.
Results. It was found that 70% of examined flares showed statistically significant oscillations. Longer periods occur less frequently than shorter ones. We also identified a relationship between the period and the duration in which the oscillations were observed.
Planetary inward migration as the potential cause of GJ 504’s fast rotation and bright X-ray luminosity
Authors: Pezzotti C. , Buldgen G. , Magaudda E. , Farnir M. , Van Grootel V. , Bellotti S. , Poppenhaeger K. 
Published: January 2025

Context. The discovery of an increasing variety of exoplanets in very close orbits around their host stars raised many questions about how stars and planets interact and to what extent host stars’ properties may be influenced by the presence of close-by companions. Understanding how the evolution of stars is impacted by the interactions with their planets is indeed fundamental to disentangling their intrinsic evolution from star-planet-interaction (SPI) induced phenomena. In this context, GJ 504 is a promising candidate for a star that underwent strong SPI. Its unusually short rotational period (Prot ∼ 3.4 days), while being in contrast with what is expected of single-star models, could result from the inward migration of a close-by, massive companion (Mpl ≥ 2 MJ), pushed towards its host by the action of tides. Moreover, its brighter emission in the X-ray luminosity may hint at a rejuvenation of the dynamo process sustaining the stellar magnetic field, which is a consequence of the SPI-induced spin-up.
Aims. We aim to study the evolution of GJ 504 and establish whether by invoking the engulfment of a planetary companion we can better reproduce its rotational period and X-ray luminosity.
Methods. We simulated the past evolution of the star by assuming two different scenarios: ‘star without close-by planet’ and ‘star with close-by planet’. In the second scenario, we use our SPI code to investigate how the inward migration and eventual engulfment of a giant planet driven by stellar tides may spin-up the stellar surface and rejuvenate its dynamo. We compare our theoretical tracks with archival-rotational-period and X-ray data of GJ 504 collected from the all-sky surveys of the ROentgen Survey with an Imaging Telescope Array (eROSITA) on board the Russian Spektrum-Roentgen-Gamma mission (SRG).
Results. Despite the large uncertainty on the stellar age, we find that the second evolutionary scenario characterised by the inward migration of a massive planetary companion is in better agreement with the short rotational period and the bright X-ray luminosity of GJ 504; thus, it strongly favours the inward migration scenario over the one in which close-by planets have no tidal impact on the star.
Extreme exomoons in WASP-49 Ab: Dynamics and detectability
Authors: Sucerquia Mario , Cuello Nicolás 
Published: January 2025

Context. WASP-49Ab, a low-density Saturn-like planet in a tight orbit around a Sun-like star within a wide binary system, is a compelling candidate for hosting a volcanic moon, as suggested by the detection of Doppler-shifted sodium.
Aims. This study evaluates the stability of potential satellites around WASP-49Ab under the influence of planetary oblateness, relativistic effects, and perturbations from a close companion star, focusing on their impact on light curve parameters such as transit duration and impact parameter variations, driven by the evolution of the planet’s orbit in this extreme environment.
Methods. Using N-body simulations and semi-analytical methods, we analysed moon’s dynamics across varied initial conditions and gravitational frameworks including the potential of an oblate planet and the effects of the general relativity.
Results. We find that ‘selenity’, a moon survival indicator, is high in close orbits with low eccentricity and near the Roche limit, especially for masses higher than Io’s. Stability decreases as eccentricity or distance from the planet increases. Additionally, we observe a strong destabilising resonance near 1.4 Rp when planetary eccentricities are considered to be ≳0.
Conclusions. This study confirms the potential for stable exomoons around WASP-49Ab despite its hostile environment, emphasising the importance of incorporating diverse physical effects in stability analyses, aiding future detection efforts.
Coronal bright point statistics
Authors: Kraus I. , Bourdin Ph.-A. , Zender J. , Bergmann M. , Hanslmeier A. 
Published: January 2025

Context. The solar corona maintains temperatures of a million Kelvin or more. The plasma heating mechanisms responsible for these extreme temperatures are still unclear. Large regions of magnetic activity in the photosphere cause extreme ultraviolet (EUV) emission in the corona. Even smaller regions with bipolar and multipolar magnetic fields can generate coronal bright points (CBPs).
Aims. We performed a statistical analysis of 346 CBPs. We used Solar Dynamics Observatory (SDO) images to track CBPs on a continuous basis. Therefore, we were able to collect a database of information on the CPB’s lifetime, shape, polarity, flux emergence, and merging behavior, as well as their magnetic evolution, using the SDO Helioseismic and Magnetic Imager (SDO-HMI) instrument.
Methods. We searched the SDO data archive for the longest continuous interval of uninterrupted observations in 2015. The longest such interval contains 12 consecutive days of full-disk images from the EUV channels of the SDO-AIA instrument. To analyze the properties of CBPs, we employed an automated tracking algorithm to follow the evolution of the CBPs. Furthermore, we manually checked the shape, underlying magnetic polarities, and merging behavior of each CBP.
Results. We provide statistics on the magnetic polarity, emergence, and merging of CBPs. We established a relationship between the CBP’s merging behavior and both its shape and magnetic polarities. Brighter CBPs are visible in all SDO-AIA channels and exhibit strong radiative energy losses. The category of CBPs with a bipolar field has the highest probability of being emissive in all SDO-AIA channels. The majority of CBPs have two opposite polarities below them.
Conclusions. The merging of two CBPs is an unusual phenomenon that is related to complex multipolar magnetic regions. Moreover, loop-shaped CBPs usually appear above bipolar fields. Faint CBPs have shorter lifetimes and are less likely to merge with another CBP.
Possible contributions of two nearby blazars to the NGC 4151 neutrino hotspot
Authors: Omeliukh A. , Barnier S. , Inoue Y. 
Published: January 2025

Context. The origin of the high-energy astrophysical neutrinos discovered by IceCube remains unclear, with both blazars and Seyfert galaxies emerging as potential sources. Recently, the IceCube Collaboration reported a ∼3σ neutrino signal from the direction of the nearby Seyfert galaxy NGC 4151. However, two gamma-ray-loud BL Lac objects, 4FGL 1210.3+3928 and 4FGL J1211.6+3901, lie close to NGC 4151, at angular distances of 0.08° and 0.43°, respectively.
Aims. We investigated the potential contribution of these two blazars to the observed neutrino signal from the direction of NGC 4151 and assessed their detectability with future neutrino observatories.
Methods. We modeled the multiwavelength spectral energy distributions (SEDs) of both blazars using a self-consistent numerical radiation code, AM3. We calculated their neutrino spectra and compared them to the measured NGC 4151 neutrino spectrum and future neutrino detector sensitivities.
Results. The SED of 4FGL 1210.3+3928 revealed a feature that cannot be explained with a purely leptonic model, suggesting the presence of protons in the jet. Our model predicts neutrino emission peaking above ∼1017 eV with fluxes of ∼10−12 erg cm−2 s−1 for this source. The SED of 4FGL J1211.6+3901 can be explained with both leptonic and leptohadronic models. The contribution of these two blazars to the ∼10 TeV neutrino signal observed from the direction of NGC 4151 can only be minor. Still, future radio-based neutrino telescopes such as IceCube-Gen2’s radio array and GRAND may be able to detect high-energy neutrinos from these two potential neutrino sources.
Olfactory Dysfunction in Children and Adolescents—A Diagnostic Pathway
Authors: Gellrich Janine , Lohrer Elisabeth C. , Hummel Thomas , Schriever Valentin A. 
Published: January 2025

AbstractOlfactory disorders have so far played a subordinate role in pediatric care, although children can also be affected. Due to a lack of awareness, the diagnosis can often only be made after numerous visits to the doctor, although it can significantly impact the quality of life. Olfactory disorders in adults are usually acquired, while congenital causes dominate in children. To date, there are no specific recommendations for diagnosis in children. This article deals with the prevalence, causes, and diagnostic approaches of olfactory disorders in pediatrics. A structured diagnostic approach is fundamental, including a medical history and psychophysical olfactory tests, supplemented by specific examinations depending on the suspected diagnosis. Therapeutic approaches are limited, with a focus on counseling and olfactory training.
Influence of Direct Oral Anticoagulant Levels and Thrombin Generation on Postoperative Bleeding [SONAR]: A Nested Case–Control Study
Authors: Shaw Joseph R. , Li Na , Grussé Matthieu , Van Dreden Patrick , St John Melanie , Nixon Joanne , Spyropoulos Alex C. , Schulman Sam , Levy Jerrold H. , Carrier Marc , Douketis James D. 
Published: January 2025

Background A direct oral anticoagulant (DOAC) concentration threshold above which an impact on surgical hemostasis starts to occur is unknown. Thrombin generation assays (TGAs) provide a measure of the coagulation phenotype. This study aimed to determine whether preoperative TGA parameters are associated with postoperative bleeding, and whether this is partly due to residual DOAC levels.
Materials and Methods We conducted a nested case–control study using samples from apixaban/rivaroxaban-treated patients with atrial fibrillation from the PAUSE (Perioperative Anticoagulation Use for Surgery Evaluation) perioperative study. Cases were participants with postoperative major or clinically relevant nonmajor bleeding; controls were participants without bleeding. DOAC levels were measured using a chromogenic anti-Xa assay (BIOPHEN DiXaI; rivaroxaban/apixaban calibrators). TGA parameters were measured using calibrated automated thrombography.Generalized linear mixed models and causal mediation analyses were used to evaluate the relationship between DOAC levels, TGA parameters, and bleeding.
Results Forty eight cases were matched to 474 controls. Residual DOAC levels were higher in cases than controls (p¼0.03) and each TGA parameter was correlated with residual DOAC levels (p<0.05). A longer lag time (LT; odds ratio [OR]¼1.319 per minute [95% confidence interval [CI]: 1.077–1.617]) and time-to-peak (TTP; OR¼1.154 per minute [95% CI: 1.028–1.296]) were associated with an increased odds of bleeding; higher peak (OR¼0.994 per nM [95% CI: 0.989–0.998]) and mean velocity rate index (mVRI; OR¼0.986 per nM/min [95% CI: 0.976–0.996]) were associated with a lower odds of bleeding. The effect of apixaban/rivaroxaban levels on bleeding was mediated by altered TGA parameters (LT, TTP, peak, mVRI).
Conclusion These findings support a measurable effect from low residual DOAC levels on thrombin generation and suggest a causal contribution of both toward bleeding.
The Use of Premedication for Intubating Very Low Birth Weight Infants in the Neonatal Intensive Care Unit: Results of a National Survey
Authors: DeMartino Cassandra , Neches Sara , Gray Megan M. , Sawyer Taylor , Johnston Lindsay 
Published: January 2025

Objective This study aimed to explore barriers and perspectives of premedication use for non-emergent intubations of very low birth weight (VLBW) infants (<1,500 g).
Study Design A cross-sectional, online survey was distributed from January to April 2023 to members of the American Academy of Pediatrics Section on Neonatal-Perinatal Medicine. Data was analyzed using descriptive statistics and chi-square tests.
Results Of the 521 respondents, the majority (81%, n = 415) were neonatologists. Over half of respondents (69%, n = 359) consider patient weight when selecting premedication. Most providers (78%, n = 407) agreed that premedication should be used for non-emergent intubation of VLBW infants, while only 41% (n = 216) felt similarly that muscle relaxants should be used. For infants over 1,500 g, 43% (n = 153) reported frequent or regular muscle relaxant use compared with 28% (n = 101) for VLBW infants. The most cited barrier to muscle relaxant use was surfactant delivery with a planned return to non-invasive support. Unit guidelines were associated with significantly more premedication and muscle relaxant use (56 vs. 44%; odds ratio [OR] = 5.2, 95% confidence interval [CI]: 3.4–7.7, p < 0.0001).
Conclusion Most neonatal providers favor premedication for non-emergent intubation but are hesitant to use muscle relaxants for VLBW infants. Premedication guidelines may facilitate the use of both premedication and muscle relaxants for this population.
Key Points
A Scalable, Chromatography-Free Synthesis of the Potent and Highly Selective ERβ Agonist EGX358
Authors: Donaldson William A. , Chaudhury Subhabrata , Thennakoon Dulanjali , Wetzel Edward A. 
Published: January 2025

Abstract4-[trans-4-(Hydroxymethyl)cyclohexyl]phenol (EGX358) is a potent and highly selective estrogen receptor beta (ERβ) agonist which has demonstrated efficacy for moderation of a chemically induced hot flash and for memory consolidation in an ovariectomized mouse model for menopause. An improved synthetic route to EGX358 is reported which proceeds in four steps and which is chromatography-free.
Proton arc therapy plan optimization with energy layer pre-selection driven by organ at risk sparing and delivery time
Authors: Wuyckens Sophie , Janssens Guillaume , Chocan Vera Macarena , Sundström Johan , Di Perri Dario , Sterpin Edmond , Souris Kevin , Lee John A 
Published: January 2025

Abstract

Objective. As proton arc therapy (PAT) approaches clinical implementation, optimizing treatment plans for this innovative delivery modality remains challenging, especially in addressing arc delivery time. Existing algorithms for minimizing delivery time are either optimal but computationally demanding or fast but at the expense of sacrificing many degrees of freedom. In this study, we introduce a flexible method for pre-selecting energy layers (EL) in PAT treatment planning before the actual robust spot weight optimization. Approach. Our EL pre-selection method employs metaheuristics to minimize a bi-objective function, considering a dynamic delivery time proxy and tumor geometrical coverage penalized as a function of selected organs-at-risk crossing. It is capable of parallelizing multiple instances of the problem. We evaluate the method using three different treatment sites, providing a comprehensive dosimetric analysis benchmarked against dynamic proton arc plans generated with early energy layer selection and spot assignment (ELSA) and IMPT plans in RayStation TPS. Result. The algorithm efficiently generates Pareto-optimal EL pre-selections in approximately 5 min. Subsequent PAT treatment plans derived from these selections and optimized within the TPS, demonstrate high-quality target coverage, achieving a high conformity index, and effective sparing of organs at risk. These plans meet clinical goals while achieving a 20%–40% reduction in delivery time compared to ELSA plans. Significance. The proposed algorithm offers speed and efficiency, producing high-quality PAT plans by placing proton arc sectors to efficiently reduce delivery time while maintaining good target coverage and healthy tissues sparing.
Identifying the current penetration depth in high-Tc superconducting bulks through levitation force measurements
Authors: Brooks Justin , Porteous Luke , Storey James G , Badcock Rodney 
Published: January 2025

Abstract
High-T

c
superconducting REBa2Cu3O

7
−
x

(REBCO) bulks are actively researched for use in superconducting magnetic bearings (SMBs). SMBs are attractive in applications which require zero friction, ultra high speeds, or integration within cryogenic environments. However, SMBs are limited by low stiffness values compared to mechanical bearings, prohibiting their use in turbulent environments such as rocketry or aviation. To improve the performance of SMBs, a comprehensive understanding of the precise distribution of currents and magnetic fields within the material during magnetic suspension is required. Hence, the results of vertical and lateral levitation force measurements between a single directional melt growth REBCO bulk and an NdFeB magnet are reported. The measurements are carried out between 77 K and 90 K and for bulk thickness between 0.5 mm to 4.5 mm. By reducing the bulk thickness, the depth to which the induced currents penetrate the bulk is identified in zero-field cooling conditions. At 77 K, the current and magnetic field occupy the top 1 mm, closest to the magnet. By reducing the bulk thickness further, the levitation force profiles vary significantly. Field-cooling results are similarly impacted; reducing the bulk thickness below 1 mm dramatically reduces the lateral stiffness. The above results are interpreted using finite element simulations employing experimentally measured Jc
(B,θ) data from the bulk, following the completion of the levitation force measurement routine. These results are relevant for future bearing designs, helping to inform the optimal distribution of superconducting material for a given application.
Markov chain-based method for degree distribution of evolving networks
Authors: Xiao Yue , Zhang Xiaojun 
Published: January 2025

Abstract
In the study of the degree distribution of evolving networks, the theoretical solution of the degree distribution of networks with node preference deletion has not been solved, and accordingly, subsequent application research based on degree distribution cannot be carried out. This paper improves the most efficient method for solving degree distribution, SPR, and proposes an enhanced stochastic process rule-based (ESPR) Markov chain method so that it can handle networks with node preference deletion. By redesigning the evolution rule, ESPR simulates the natural evolution process of networks with node transfer and keeps the topological structure and statistical properties of the network in ESPR consistent with it. Then, based on this rule, the change of network degree distribution can be characterized by the Markov chain, which significantly reduces the complexity of solving the nonlinear problem of node preference deletion. We use two theorems to show that this method not only targets the degree distribution of networks with node preference deletion but is also compatible with the functions of SPR, providing a complete theoretical framework for solving degree distribution. In addition, the method proposed in this paper can be used to study the instantaneous attitude distribution of networks and can be applied to more complex statistical discussions such as degree correlation.
Azimuthal correlation anisotropies in p + p collisions simulated using Pythia*
Authors: Torres Manuel Sebastian , Feng 冯 Yicheng 毅程 , Wang 王 Fuqiang 福强 
Published: January 2025

Abstract
Stimulated by a keen interest in possible collective behavior in high-energy proton-proton and proton-nucleus collisions, we study two-particle angular correlations in pseudorapidity and azimuthal differences in simulated p + p interactions using the Pythia 8 event generator. Multi-parton interactions and color connection are included in these simulations, which have been perceived to produce collectivity in final-state particles. Meanwhile, contributions from genuine few-body nonflow correlations, not of collective flow behavior, are known to be severe in these small-system collisions. We present our Pythia correlation studies pedagogically and report azimuthal harmonic anisotropies analyzed using several methods. We observe anisotropies in these Pythia simulated events qualitatively and semi-quantitatively, similar to experimental data. Our findings highlight the delicate nature of azimuthal anisotropies in small-system collisions and provide a benchmark that can aid in improving data analysis and interpreting experimental measurements in small-system collisions.
Experimental identification of I-mode characteristics at the edge of FIRE mode in KSTAR
Authors: Heo Chweeho , Park SangJin , Choi GyungJin , Kim Jaewook , Kim Eun-jin , Jeon YoungMu , Choi Minjun J. , Han Hyunsun , Sung Choongki , Hahm TaikSoo , Na Yong-Su 
Published: January 2025

Abstract
The edge region of the recently discovered fast ion-regulated enhancement mode (FIRE mode) (Han and Park et al 2022 Nature
609 269–275), which primarily operates in the unfavorable ion

∇
B

drift configuration, is investigated in detail for the first time. An ion temperature pedestal is identified, while the edge electron density profile remains at low-confinement mode (L-mode) level, displaying characteristics of the edge profiles in improved energy confinement mode (I-mode). The weakly coherent mode (WCM) is observed at around 50 kHz in the spectrum of edge electron density fluctuations measured by beam emission spectroscopy. The weakly coherent feature becomes more pronounced as the amplitude of intermediate-frequency fluctuations (approximately 10–30 kHz) decreases, coinciding with a rise in the height of the temperature pedestal. The WCM propagates in the ion diamagnetic drift direction in the laboratory frame, but its propagation direction in the E × B flow frame has yet to be determined. Nonlinear phase coupling between the low-frequency density fluctuation components and the WCMs is identified, indicating the presence of zonal density. This coupling typically occurs as the H-mode transition approaches, and its potential link to a regulatory process is discussed. When the coupling manifests, intermittent bursts are observed concurrently, not just at the radial location where the WCM amplitude peaks, but throughout the edge region. No other coherent oscillations with finite frequency have been detected thus far.