bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constraints on the Evolution of the Ionizing Background and Ionizing Photon Mean Free Path at the End of Reionization
Authors: Davies Frederick B. , Bosman Sarah E. I. , Gaikwad Prakash , Nasir Fahad , Hennawi Joseph F. , Becker George D. , Haehnelt Martin G. , D’Odorico Valentina , Bischetti Manuela , Eilers Anna-Christina , Keating Laura C. , Kulkarni Girish , Lai Samuel , Mazzucchelli Chiara , Qin Yuxiang , Satyavolu Sindhu , Wang Feige , Yang Jinyi , Zhu Yongda 
Published: April 2024

Abstract
The variations in Lyα forest opacity observed at z > 5.3 between lines of sight to different background quasars are too strong to be caused by fluctuations in the density field alone. The leading hypothesis for the cause of this excess variance is a late, ongoing reionization process at redshifts below six. Another model proposes strong ionizing background fluctuations coupled to a short, spatially varying mean free path of ionizing photons, without explicitly invoking incomplete reionization. With recent observations suggesting a short mean free path at z ∼ 6, and a dramatic improvement in z > 5 Lyα forest data quality, we revisit this latter possibility. Here, we apply the likelihood-free inference technique of approximate Bayesian computation (ABC) to jointly constrain the hydrogen photoionization rate ΓHI and the mean free path of ionizing photons λ
mfp from the effective optical depth distributions at z = 5.0–6.1 from XQR-30. We find that the observations are well-described by fluctuating mean free path models with average mean free paths that are consistent with the steep trend implied by independent measurements at z ∼ 5–6, with a concomitant rapid evolution of the photoionization rate.
Tracing the Galactic Disk with the Kinematics of Gaia Cepheids
Authors: Zhou Xiaoyue , Chen Xiaodian , Deng Licai , Wang Shu 
Published: April 2024

Abstract
Classical Cepheids (CCs) are excellent tracers for understanding the structure of the Milky Way disk. The latest Gaia Data Release 3 provides a large number of line-of-sight velocity information for Galactic CCs, offering an opportunity for studying the kinematics of the Milky Way. We determine the 3D velocities of 2057 CCs relative to the Galactic center. From the projections of the 3D velocities onto the X–Y plane of the Galactic disk, we find that the V

R
and V

ϕ
velocities of the northern and southern warps (directions with highest amplitude) are different. This phenomenon may be related to warp precession or asymmetry in warp structure. By investigating the kinematic warp model, we find that the vertical velocities of CCs are more suitable for constraining the warp precession rate than the line-of-node angle. Our results suggest that CCs at 12–14 kpc are the best sample for determining the Galactic warp precession rate. Based on the spatial structure parameters of Cepheid warp from Chen et al., we determine a warp precession rate of ω = 4.9 ± 1.6 km s−1 kpc−1 at 13 kpc, which supports a low precession rate in the warp model. In the future, more kinematic information on CCs will help to constrain the structure and evolution of the Milky Way better.
Investigating 56 High Galactic Latitude Open Cluster Candidates in
Gaia DR3
Authors: Wu You , Chen Jing , Zhang Su , Wei Xingyin , He Feilong , Zhao Yunbo , He Xuran 
Published: April 2024

Abstract
Using Gaia DR3 data, we revisit 56 high Galactic latitude (∣b∣ ≥ 30°) open cluster (OC) candidates with poor shapes of
color–magnitude diagrams (CMDs), including unclear and paired main sequences
(MSs). We aim to confirm their physical reality and explore whether the special
MS morphology is intrinsic to genuine OCs. Initially, we redetermine cluster
memberships by integrating five outlier detection algorithms into pyUPMASK.
However, this work fails to reproduce the 56 clusters. Instead, we find an
alternative set of 56 clusters, six of which are non-duplicates. To ascertain
whether the six clusters are real OCs, we build synthetic CMDs to derive
reliable cluster properties, including fundamental parameters, binary fraction,
and mass of the cluster. Subsequently, we investigate the structural parameters
and the age–mass and mass–radius relations of the six candidate OCs. Finally, we
utilize a multidimensional approach, incorporating cluster properties, spatial
structure, kinematic attributes, and CMD verification, to assess their physical
reality as genuine OCs further. Our results suggest that the six candidates
should be physical OCs, exhibiting well-defined CMD characteristics. Moreover,
we discover two of the six OCs as potential binary clusters.
Concise Spectrotemporal Studies of Magnetar SGR J1935+2154 Bursts
Authors: Keskin Özge , Göğüş Ersin , Kaneko Yuki , Demirer Mustafa , Yamasaki Shotaro , Baring Matthew G. , Lin Lin , Roberts Oliver J. , Kouveliotou Chryssa 
Published: April 2024

Abstract
SGR J1935+2154 has truly been the most prolific magnetar over the last decade: it has been entering into burst active episodes once every 1–2 yr since its discovery in 2014, it emitted the first Galactic fast radio burst associated with an X-ray burst in 2020, and it has emitted hundreds of energetic short bursts. Here, we present the time-resolved spectral analysis of 51 bright bursts from SGR J1935+2154. Unlike conventional time-resolved X-ray spectroscopic studies in the literature, we follow a two-step approach to probe true spectral evolution. For each burst, we first extract spectral information from overlapping time segments, fit them with three continuum models, and employ a machine-learning-based clustering algorithm to identify time segments that provide the largest spectral variations during each burst. We then extract spectra from those nonoverlapping (clustered) time segments and fit them again with the three models: the cutoff power-law model, the sum of two blackbody functions, and the model considering the emission of a modified blackbody undergoing resonant cyclotron scattering, which is applied systematically at this scale for the first time. Our novel technique allowed us to establish the genuine spectral evolution of magnetar bursts. We discuss the implications of our results and compare their collective behavior with the average burst properties of other magnetars.
Constraining the PG 1553+113 Binary Hypothesis: Interpreting Hints of a New, 22 yr Period
Authors: Adhikari S. , Peñil P. , Westernacher-Schneider J. R. , Domínguez A. , Ajello M. , Buson S. , Rico A. , Zrake J. 
Published: April 2024

Abstract
PG 1553+113 is a well-known blazar exhibiting evidence of a ∼2.2 yr quasiperiodic oscillation (QPO) in the radio, optical, X-ray, and γ-ray bands. Since QPO mechanisms often predict multiple QPOs, we search for a second QPO in its historical optical light curve covering a century of observations. Despite challenging data quality issues, we find hints of a 21.8 ± 4.7 yr oscillation. On its own, this ∼22 yr period has a modest statistical significance of 1.6σ when accounting for the look-elsewhere effect. However, the joint significance of both the 2.2 and 22 yr periods arising from colored noise alone is ∼3.6σ. The next peak of the 22 yr oscillation is predicted to occur around July 2025. We find that such a ∼10:1 relation between two periods can arise in the gas dynamics of a plausible supermassive black hole binary model of PG 1553+113. While the 22 yr QPO is preliminary, an interpretation of PG 1553+113's two QPOs in this binary model suggests that the binary engine has a mass ratio ≳0.2, an eccentricity ≲0.1, and accretes from a disk with characteristic aspect ratio ∼0.03. The putative binary radiates nHz gravitational waves, but the amplitude is ∼10–100 times too low for detection by foreseeable pulsar timing arrays.
Multifrequency Very Long Baseline Interferometry Imaging of the Subparsec-scale Jet in the Sombrero Galaxy (M104)
Authors: Yan Xi , Lu Ru-Sen , Jiang Wu , Krichbaum Thomas P. , Xie Fu-Guo , Shen Zhi-Qiang 
Published: April 2024

Abstract
We report multifrequency and multiepoch very long baseline interferometry studies of the subparsec jet in the Sombrero galaxy (M104, NGC 4594). Using Very Long Baseline Array data at 12, 22, 44, and 88 GHz, we study the kinematics of the jet and the properties of the compact core. The subparsec jet is clearly detected at 12 and 22 GHz, and the inner jet base is resolved down to ∼70 Schwarzschild radii (R
s) at 44 GHz. The proper motions of the jet are measured with apparent subrelativistic speeds of 0.20 ± 0.08c and 0.05 ± 0.02c for the approaching and the receding jet, respectively. Based on the apparent speed and jet-to-counterjet brightness ratio, we estimate the jet viewing angle to be larger than ∼37°, and the intrinsic speed to be between ∼0.10c and 0.40c. Their joint probability distribution suggests the most probable values of the viewing angle and intrinsic speed to be

66
°

−
6
°

+
4
°

and 0.19 ± 0.04c, respectively. We also find that the measured brightness temperatures of the core at 12, 22, and 44 GHz are close to the equipartition brightness temperature, indicating that the energy density of the radiating particles is comparable to the energy density of the magnetic field in the subparsec jet region. Interestingly, the measured core size at 88 GHz (∼25 ± 5 R
s) deviates from the expected frequency dependence seen at lower frequencies. This may indicate a different origin for the millimeter emission, which can be explained by an advection-dominated accretion flow (ADAF) model. This model further predicts that at 230 and 340 GHz, the ADAF may dominate the radio emission over the jet.
The ΛCDM-NG Cosmological Model: A Possible Resolution of the Hubble Tension
Authors: Cook Richard J. 
Published: April 2024

Abstract
We offer a cosmological model based on conventional general relativity (no speculative physics) that may resolve the Hubble tension. A reanalysis of the foundation of the Lambda-CDM model shows that general relativity alone does not specify what fraction of the mass density acts as the source term in Friedmann’s equation and what fraction acts as the source of the gravitational potential of condensed objects. This observation opens the way to alternative cosmological models within conventional general relativity, and it proves that the ΛCDM model is not the unique solution of Einstein’s equations for the usual cosmological sources of gravitation. We emphasize that the source of the gravitation potential in the ΛCDM model is the deviation δ
ρ

m
of the mass density away from its average value, and not the total density of condensed masses as in Newtonian theory. Though not often stated, this is a modification of Newtonian gravitation within the ΛCDM model. The ΛCDM-NG model uses the freedom to move matter between source terms to restore the source of gravitational potential to its Newtonian form. There is no Hubble tension in the ΛCDM-NG model if the gravitational potential of condensed objects (stars, galaxies, and dark matter clouds) falls in a certain range, a range that does not seem unreasonable for the actual Universe. The deceleration parameter in the ΛCDM-NG model differs from that in the ΛCDM model, suggesting a test to distinguish between the two models.
Rotational Spectrum and First Interstellar Detection of 2-methoxyethanol Using ALMA Observations of NGC 6334I
Authors: Fried Zachary T. P. , El-Abd Samer J. , Hays Brian M. , Wenzel Gabi , Byrne Alex N. , Margulès Laurent , Motiyenko Roman A. , Shipman Steven T. , Horne Maria P. , Jørgensen Jes K. , Brogan Crystal L. , Hunter Todd R. , Remijan Anthony J. , Lipnicky Andrew , Loomis Ryan A. , McGuire Brett A. 
Published: April 2024

Abstract
We use both chirped-pulse Fourier transform and frequency-modulated absorption spectroscopy to study the rotational spectrum of 2-methoxyethanol (CH3OCH2CH2OH) in several frequency regions ranging from 8.7 to 500 GHz. The resulting rotational parameters permitted a search for this molecule in Atacama Large Millimeter/submillimeter Array (ALMA) observations toward the massive protocluster NGC 6334I, as well as source B of the low-mass protostellar system IRAS 16293−2422. A total of 25 rotational transitions are observed in the ALMA Band 4 data toward NGC 6334I, resulting in the first interstellar detection of 2-methoxyethanol. A column density of

1.3

−
0.9

+
1.4

×

10

17

cm−2 is derived at an excitation temperature of

143

−
39

+
31

K. However, molecular signal is not observed in the Band 7 data toward IRAS 16293−2422B, and an upper-limit column density of 2.5 × 1015 cm−2 is determined. Various possible formation pathways—including radical recombination and insertion reactions—are discussed. We also investigate physical differences between the two interstellar sources that could result in the observed abundance variations.
History of Ceres’s Cold Traps Based on Refined Shape Models
Authors: Schorghofer Norbert , Gaskell Robert , Mazarico Erwan , Weirich John 
Published: April 2024

Abstract
Permanently shadowed regions (PSRs) in the north polar region of Ceres have been previously mapped by the Dawn spacecraft. Putative ice deposits are found in some of these PSRs, whereas most PSRs host no bright deposits, which is thought to be due to oscillations of the axis tilt with a ∼25 ka period. We use stereophotoclinometry to construct refined topographic models of PSR-hosting craters. Ray-tracing calculations reveal that no PSRs remain at the maximum axis tilt, which implies that the ice deposits are remarkably young. The bright ice deposits do not extend beyond PSRs at an axis tilt of 10°, which last occurred about 6 ka ago. This suggests that water is delivered to the polar regions or exposed within the craters by frequent and short-lived events. Surface temperatures are calculated with a terrain irradiance model to delineate cold traps. Based on maximum equilibrium temperatures, Cerean PSRs are too warm to trap supervolatiles.
Knowledge of and Stated Adherence to the 2020 ACR Guideline for Gout Management: Results of a Survey of US Rheumatologists
Authors: Schlesinger Naomi , Pillinger Michael H. , Lipsky Peter E. 
Published: April 2024

ObjectiveThis report evaluates rheumatologists' stated adherence to and agreement with the 2020 American College of Rheumatology (ACR) Guideline for the Management of Gout.MethodsA 57-item questionnaire was administered to a sample of US rheumatologists. Stated adherence scores were based on several guideline recommendations reported to be followed by rheumatologists in practice, whereas stated agreement scores were based on whether respondents always followed the recommendations.ResultsAll 201 rheumatologists approached completed the questionnaire. The mean overall stated adherence score was 11.5 (maximum 15), whereas the mean overall stated agreement score was 7.7 (maximum 14). Less experienced rheumatologists (≤ 8 yrs; n = 49) were likely to claim adherence to more individual ACR recommendations than those with more experience (> 8 yrs; n = 152; mean stated adherence score: 12.3 vs 11.3;P≤ 0.05). Rheumatologists who claimed to see ≤ 75 patients with gout in 6 months (n = 66) had a mean stated adherence score of 12.1 vs 11.2 for those who claimed to have seen > 75 patients (P≤ 0.05). Approximately 78% of rheumatologists claimed to follow the guideline for initiating urate-lowering therapy (ULT), and 89% were likely to prescribe allopurinol as a first-line ULT. Claimed adherence to recommendations for dosing was lower (febuxostat: 43%; allopurinol: 39%). Rheumatologists from academic settings were more likely to prescribe an interleukin-1 inhibitor for gout flares.ConclusionThe self-reported practice of the surveyed US rheumatologists was generally concordant with the 2020 ACR Guideline for the Management of Gout. However, there were gaps in guideline knowledge and stated adherence among rheumatologists, mainly concerning the dosing of treatment regimens.
Feasibility of Physiotherapist-Led Rheumatology Triage: A Randomized Study
Authors: Roberts Janet H. , Gunn Cheri , Mackinnon Jennifer E. , Parlee Susan , Bakowsky Volodko , Taylor Trudy , Barber Claire E.H. , Hanly John G. 
Published: April 2024

ObjectiveGiven global shortages in the rheumatology workforce, the demand for rheumatology assessment often exceeds the capacity to provide timely access to care. Accurate triage of patient referrals is important to ensure appropriate utilization of finite resources. We assessed the feasibility of physiotherapist (PT)-led triage using a standardized protocol in identifying cases of inflammatory arthritis (IA), as compared to usual rheumatologist triage of referrals for joint pain, in a tertiary care rheumatology clinic.MethodsWe performed a single-center, prospective, nonblinded, randomized, parallel-group feasibility study with referrals randomized in a 1:1 ratio to either PT-led vs usual rheumatologist triage. Standardized information was collected at referral receipt, triage, and clinic visit. Rheumatologist diagnosis was considered the gold standard for diagnosis of IA.ResultsOne hundred two referrals were randomized to the PT-led triage arm and 101 to the rheumatologist arm. In the PT-led arm, 65% of referrals triaged as urgent were confirmed to have IA vs 60% in the rheumatologist arm (P= 0.57), suggesting similar accuracy in identifying IA. More referrals were declined in the PT-led triage arm (24 vs 8,P= 0.002), resulting in fewer referrals triaged as semiurgent (6 vs 23,P= 0.003). One case of IA (rheumatologist arm) was incorrectly triaged, resulting in significant delay in time to first assessment.ConclusionPT-led triage was feasible, appeared as reliable as rheumatologist triage of referrals for joint pain, and led to significantly fewer patients requiring in-clinic visits. This has implications for waitlist management and optimal rheumatology resource utilization.
Le nouveau paradis artificiel
Authors: Susca Vincenzo 
Published: April 2024

Après une longue période où la technique a joué surtout le rôle d’instrument au service de l’être humain, nous nous trouvons aujourd’hui dans un système intégral d’informations, de machines, d’algorithmes et de réseaux, dont les intelligences artificielles sont la dernière manifestation, si puissant que, après en avoir définitivement perdu le contrôle, c’est nous-mêmes qui dérivons d’eux. Nous sommes pris dans leurs rets, qui nous enveloppent et nous attachent à tout ce qui est autre. Happé par une spirale contagieuse, l’être humain devient à la fois chose, information, spectacle, marchandise, œuvre d’art et artiste. Il se défait de sa propre identité́ pour se dissoudre dans l’altérité́ et se retrouver autre que soi. Nous voici comme autant de technomagiciens et de cobayes volontaires d’une expérimentation totalisante sur la vie à venir, en temps réel. Dans ce scénario, les IA ne se limitent pas, selon les utopies modernes, à travailler à notre place. Elles finissent par agir avec nous – et même par nous remplacer – dans les domaines jadis exclus à l’emprise technique : l’art, la création, le jeu…
Complexité et « machine artificielle » selon Edgar Morin
Authors: Nsonsissa Auguste 
Published: April 2024

Cette réflexion est destinée à examiner les éléments logico-philosophiques indispensables à la compréhension du rapport entre la complexité et la machine artificielle, d’une part, puis entre l’intelligence artificielle et ses considérations méta-éthiques, d’autre part. Il se trouve que, depuis quelque temps déjà, l’intelligence artificielle prend une importance considérable dans l’informatisation de notre société. Parallèlement, la philosophie de la technoscience tend à répandre la notion de machine artificielle dans tous les univers du savoir. En témoigne le point de vue d’Edgar Morin dans l’axe méthodologique de la pensée complexe, dont il fixe les repères en rapport avec l’hypothèse du computo . Paradoxalement, la machine artificielle prête à équivoque, conformément aux exigences métaphysiques de l’esprit. L’artificiel est en passe de se placer au premier rang des neurosciences. Qui plus est, à l’aune des techniques dites d’imagerie, non sans résonance magnétique fonctionnelle, il se tourne vers le développement intense des artefacts techniques dans les sciences de l’ingénieur et dans des champs pluridisciplinaires qui sont de plus en plus innovants, mais précisons que les conditions de possibilité d’une machine artificielle ne sont pas toujours réductibles à celles d’une intelligence artificielle. S’ouvre alors l’axe épistémologique de la complexité de l’intelligence humaine doublée de l’intelligence de la complexité de Leibniz à Morin.
Monter dans les nuages et la brume
Authors: Xu Yi Bing , Deng Rui 
Published: April 2024

L’auteur examine les racines de l’image et le sens du dragon chinois dans le domaine de l’imaginaire, couvrant un large spectre allant des mythes antiques à la société contemporaine. La recherche commence par l’analyse du symbolisme du dragon dans les mythes anciens, révélant son étroite connexion avec la prédominance culturelle, puis elle explore les multiples symbolismes du dragon dans la culture traditionnelle chinoise, incluant ceux du pouvoir impérial, l’autorité et les symboles de bonheur et de bienfaits. L’auteur explore ensuite le domaine de l’imagination artistique : analyse détaillée des images de dragons dans les œuvres littéraires ainsi que de leur représentation imaginaire dans les formes d’art, telles que la peinture, la sculpture et la danse. Sur cette base, il examine l’influence et l’évolution du dragon chinois dans la société contemporaine, en particulier dans les médias culturels actuels, tels le cinéma, l’animation et les jeux vidéo. Enfin, l’article résume l’évolution de l’image et du sens du dragon dans l’imaginaire en mettant l’accent sur ses transformations continuelles et ses enrichissements tout au long de l’histoire puis propose des directions et des perspectives de recherche pour l’avenir.
Forest tent caterpillar (Lepidoptera: Lasiocampidae) across Canada, 1938–2001: II. Emergent periodicity from asynchronous eruptive anomalies
Authors: Cooke Barry J. 
Published: April 2024

Abstract
Using aerial sketch map data spanning more than 1 000 000 km2 across Canada, I use cluster analysis to show that outbreaks of forest tent caterpillar, Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae), through the 20th century have occurred regularly every decade or so; however, there are two distinct aspects to the patterning of outbreaks. The dominant mode of variability is a nonrecurring pattern of singular spike anomalies, lasting just a few years, that are regional in extent but are not synchronised across the country. The regional time series derived from cluster analysis that are dominated by these singular spike eruptions exhibit extreme skewness and kurtosis, are not stationary in mean or variance, and are not amenable to classical time-series analysis. Although these regional-scale eruptive anomalies tend to occur periodically in aggregate, their central location always varies in an unpredictable manner, resulting in aperiodic local behaviour. Range-wide periodicity is thus an emergent property from asynchronous, aperiodic eruptions aggregated across regions. The second mode of variability is a low-amplitude fluctuation of weak periodicity that is weakly synchronised across the country. These observations support a hybrid cyclic–eruptive theory of outbreak occurrence that is not consistent with the simpler idea of spatially synchronised cycling.