bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma lensing with magnetic field and a small correction to the Faraday rotation measurement
Authors: Er Xinzhong , Pen Ue-Li , Sun Xiaohui , Li Dongzi 
Published: April 2023

ABSTRACT
Plasma lensing displays interesting characteristics that set it apart from gravitational lensing. The magnetized medium induces birefringence in the two polarization modes. As the lensing deflection grows stronger, e.g. when images form near the critical curve, the geometric delay of the signal can cause rotation in linear polarization, in addition to Faraday rotation. This rotation has a frequency dependence to the power of four. We study the geometric rotation of the lensed image in a Gaussian density model and find that it is necessary to take into account the geometric rotation when estimating magnetized media, especially in the underdense lens. At frequencies of ∼1 GHz or lower, the geometric rotation can dominate. We simulate the flux of lensed images and find that when the image forms near the lensing critical curve, the birefringence can convert the linear polarization and un-polarization pulse into a circular mode. The lensing magnification has the potential to increase the probability of detecting such events.
The VANDELS survey: the ionizing properties of star-forming galaxies at 3 ≤ z ≤ 5 using deep rest-frame ultraviolet spectroscopy
Authors: Saldana-Lopez A , Schaerer D , Chisholm J , Calabrò A , Pentericci L , Cullen F , Saxena A , Amorín R , Carnall A C , Fontanot F , Fynbo J P U , Guaita L , Hathi N P , Hibon P , Ji Z , McLeod D J , Pompei E , Zamorani G 
Published: April 2023

ABSTRACT
The physical properties of Epoch of Reionization (EoR) galaxies are still poorly constrained by observations. To better understand the ionizing properties of galaxies in the EoR, we investigate deep, rest-frame ultraviolet (UV) spectra of ≃500 star-forming galaxies at 3 ≤ z ≤ 5 selected from the public ESO-VANDELS spectroscopic survey. The absolute ionizing photon escape fraction ($f_{\rm esc}^{\rm abs}$, i.e. the ratio of leaking against produced ionizing photons) is derived by combining absorption line measurements with estimates of the UV attenuation. The ionizing production efficiency (ξion, i.e. the number of ionizing photons produced per non-ionizing UV luminosity) is calculated by fitting the far-UV (FUV) stellar continuum of the VANDELS galaxies. We find that the $f_{\rm esc}^{\rm abs}$ and ξion parameters increase towards low-mass, blue UV-continuum slopes and strong Ly α emitting galaxies, and both are slightly higher-than-average for the UV-faintest galaxies in the sample. Potential Lyman Continuum Emitters (LCEs, $f_{\rm esc}^{\rm abs} \ge 5{{\ \rm \, per\ cent}}$) and selected Lyman Alpha Emitters (LAEs, WLyα ≤ −20 Å) show systematically higher ξion (log ξion(Hz erg−1) ≈ 25.38, 25.41) than non-LCEs and non-LAEs (log ξion(Hz erg−1) ≈ 25.18, 25.14) at similar UV magnitudes. This indicates very young underlying stellar populations (≈10 Myr) at relatively low metallicities (≈0.2 Z⊙). The FUV non-ionizing spectra of potential LCEs is characterized by blue UV slopes (≤−2), enhanced Ly α emission (≤−25 Å), strong UV nebular lines (e.g. high ${\rm C\, \small {IV}}$1550/${\rm C\, \small {III}}$1908 ≥0.75 ratios), and weak absorption lines (≤1 Å). The latter suggests the existence of low gas-column-density channels in the interstellar medium, which enables the escape of ionizing photons. By comparing our VANDELS results against other surveys in the literature, our findings imply that the ionizing budget in the EoR was likely dominated by UV-faint, low-mass, and dustless galaxies.
Deviation in stellar trajectory induced by asymmetry in partial tidal disruption
Authors: Banerjee Pritam , Garain Debojyoti , Chowdhury Shaswata , Singh Dhananjay , Joshi Rohan , Sarkar Tapobrata 
Published: April 2023

ABSTRACT
We study partial tidal disruption and present a quantitative analysis of the orbital dynamics of the remnant self-bound core. We perform smoothed particle hydrodynamical simulations to show that partial disruption of a star due to the tidal field of a black hole leads to a jump in the specific orbital energy and angular momentum of the core. It directly leads to deviation in the core’s trajectory apart from getting a boost in its velocity. Our analysis shows that the variations in the specific orbital energy and angular momentum are higher when the pericenter distance is lower. We conclude that higher mass asymmetry of the two tidal tails increases the magnitude of the trajectory deviations. We show that observable deviations are only possible when mass ratio $q \lesssim \mathcal {O}(10^3)$ , which indicates the range of intermediate-mass black holes.
Torque reversal and cyclotron absorption feature in HMXB 4U 1538−522
Authors: Sharma Prince , Jain Chetana , Dutta Anjan 
Published: April 2023

ABSTRACT
We present a comprehensive timing and spectral analysis of the HMXB 4U 1538−522 by using the Nuclear Spectroscopic Telescope Array (NuSTAR) observatory data. Using three archived observations made between 2019 and 2021, we have detected ∼ 526 s coherent pulsations up to 60 keV. We have found an instantaneous spin-down rate of $\dot{P} = 6.6_{-6.0}^{+2.4} \times 10^{-6}$ s s−1 during the first observation. The pulse profiles had a double peaked structure consisting of a broad primary peak and an energy dependent, weak secondary peak. We have also analysed the long-term spin period evolution of 4U 1538−522 from data spanning more than four decades, including the data from Fermi/GBM. Based on the recent spin trends, we have found that the third torque reversal in 4U 1538−522 happened around MJD 58800. The source is currently spinning up with $\dot{P} = -1.9(1) \times 10^{-9}$ s s−1. We also report a periodic fluctuation in the spin period of 4U 1538−522. The broad-band persistent spectra can be described with a blackbody component and either power law or Comptonization component along with a Fe Kα line at 6.4 keV and a cyclotron absorption feature around 22 keV. We have also found a relatively weak absorption feature around 27 keV in the persistent spectra of 4U 1538−522 in all three observations. We have estimated a magnetic field strength of $1.84_{-0.06}^{+0.04} (1+z) \times 10^{12}$ and $2.33_{-0.24}^{+0.15} (1+z) \times 10^{12}$  G for the two features, respectively.
Effects of dust grain size distribution on the abundances of CO and H2 in galaxy evolution
Authors: Hirashita Hiroyuki 
Published: April 2023

ABSTRACT
We model the effect of grain size distribution in a galaxy on the evolution of CO and H2 abundances. The formation and dissociation of CO and H2 in typical dense clouds are modelled in a manner consistent with the grain size distribution. The evolution of grain size distribution is calculated based on our previous model, which treats the galaxy as a one-zone object but includes various dust processing mechanisms in the interstellar medium (ISM). We find that typical dense clouds become fully molecular (H2) when the dust surface area increases by shattering while an increase of dust abundance by dust growth in the ISM is necessary for a significant rise of the CO abundance. Accordingly, the metallicity dependence of the CO-to-H2 conversion factor, XCO, is predominantly driven by dust growth. We also examine the effect of grain size distribution in the galaxy by changing the dense gas fraction, which controls the balance between coagulation and shattering, clarifying that the difference in the grain size distribution significantly affects XCO even if the dust-to-gas ratio is the same. The star formation time-scale, which controls the speed of metal enrichment also affects the metallicity at which the CO abundance rapidly increases (or XCO drops). We also propose dust-based formulae for XCO, which need further tests for establishing their usefulness.
Identifying LISA verification binaries among the Galactic population of double white dwarfs
Authors: Finch Eliot , Bartolucci Giorgia , Chucherko Daniel , Patterson Ben G , Korol Valeriya , Klein Antoine , Bandopadhyay Diganta , Middleton Hannah , Moore Christopher J , Vecchio Alberto 
Published: April 2023

ABSTRACT
Double white dwarfs (DWDs) will be the most numerous gravitational-wave (GW) sources for the Laser Interferometer Space Antenna (LISA). Most of the Galactic DWDs will be unresolved and will superpose to form a confusion noise foreground, the dominant LISA noise source around ${\sim} 0.5\!-\!3\, \mathrm{mHz}$ . A small fraction of these sources will stand out from the background and be individually detectable. Uniquely among GW sources, a handful of these binaries will be known in advance from electromagnetic (EM) observations and will be guaranteed sources of detectable GWs in the LISA band; these are known as verification binaries (VBs). High-cadence photometric surveys are continuously discovering new VB systems, and their number will continue to grow ahead of the launch of LISA. We analyse, in a fully Bayesian framework, all the currently known VB candidates with the latest design requirements for the LISA mission and find that 25 of the considered sources can be detected within a 4 yr observation time. We explore what can be expected from GW observations, both alone and in combination with EM observations, and estimate the VB’s time to detection in the early months of LISA operations. We also show how VBs can be analysed in the case where their GW signals compete with many other unknown binary signals (both resolved and unresolved) from a realistic Galactic population of DWDs.
The Pristine survey – XXI. Exploring the metal-poor boundary with ESPaDoNS
Authors: Lombardo Linda , Bonifacio Piercarlo , Caffau Elisabetta , François Patrick , Jablonka Pascale , Kordopatis Georges , Martin Nicolas , Starkenburg Else , Yuan Zhen , Sbordone Luca , Sestito Federico , Hill Vanessa , Venn Kim 
Published: April 2023

ABSTRACT
In this paper, we study high-resolution spectra of 19 stars that have metallicity estimates below –3.5 using at least two metallicity-sensitive photometric indices based on Pristine photometry. The purpose is to understand what kind of stars populate this parameter space, together with extremely metal-poor stars. This because we plan to extensively use the Pristine photometry to provide extremely metal-poor targets to the WEAVE spectroscopic survey and wish to understand the nature of possible contaminants. We find that this extreme sample of stars is heavily contaminated by variable stars, in particular short period eclipsing binaries. We thus found, serendipitously, eight double-lined spectroscopic eclipsing binaries that could be followed-up in future studies to provide reliable masses and distances for these systems. We also found two stars that have metallicity below –3.0, one of which may belong to the Gaia-Sausage-Enceladus structure. The lesson to be learned from this investigation is that to select truly metal-poor stars one should be able to remove all photometrically variable stars, which requires complementary information beyond the Pristine photometry. We show how the Gaia photometry can be used to remove about 85 per cent of the photometrically variable stars. Our investigation also shows that there is a clear potential for Pristine photometry to find double-lined spectroscopic binaries among short period eclipsing binaries.
Aligning Retrograde Nuclear Cluster Orbits with an Active Galactic Nucleus Accretion Disc
Authors: Nasim Syeda S , Fabj Gaia , Caban Freddy , Secunda Amy , Ford K E Saavik , McKernan Barry , Bellovary Jillian M , Leigh Nathan W C , Lyra Wladimir 
Published: April 2023

ABSTRACT
Stars and stellar remnants orbiting a supermassive black hole (SMBH) can interact with an active galactic nucleus (AGN) disc. Over time, prograde orbiters (inclination i &lt; 90°) decrease inclination, as well as semimajor axis (a) and eccentricity (e) until orbital alignment with the gas disc (‘disc capture’). Captured stellar-origin black holes (sBH) add to the embedded AGN population that drives sBH–sBH mergers detectable in gravitational waves using LIGO–Virgo–KAGRA or sBH–SMBH mergers detectable with Laser Interferometer Space Antenna. Captured stars can be tidally disrupted by sBH or the SMBH or rapidly grow into massive ‘immortal’ stars. Here, we investigate the behaviour of polar and retrograde orbiters (i ≥ 90°) interacting with the disc. We show that retrograde stars are captured faster than prograde stars, flip to prograde orientation (i &lt; 90°) during capture, and decrease a dramatically towards the SMBH. For sBH, we find a critical angle iret ∼ 113°, below which retrograde sBH decay towards embedded prograde orbits (i → 0°), while for io &gt; iret sBH decay towards embedded retrograde orbits (i → 180°). sBH near polar orbits (i ∼ 90°) and stars on nearly embedded retrograde orbits (i ∼ 180°) show the greatest decreases in a. Whether a star is captured by the disc within an AGN lifetime depends primarily on disc density, and secondarily on stellar type and initial a. For sBH, disc capture time is longest for polar orbits, low-mass sBH, and lower density discs. Larger mass sBH should typically spend more time in AGN discs, with implications for the spin distribution of embedded sBH.
Race/Ethnicity and Gender Representation in Hematology and Oncology Editorial Boards: What is the State of Diversity?
Authors: Patel Shruti R , Riano Ivy , Abuali Inas , Ai Angela , Geiger Gabriella , Pimienta Jacqueline , Ramirez Roggio Adriana , Dhawan Natasha , Dizman Nazli , Lizette Salinas Alexandra , Pomares-Millan Hugo , Florez Narjust 
Published: April 2023

Abstract

Introduction
Women and underrepresented groups in medicine hold few academic leadership positions in the field of hematology/oncology. In this study, we assessed gender and race/ethnicity representation in editorial board positions in hematology/oncology journals.

Materials and Methods
Editorial leadership board members from 60 major journals in hematology and oncology were reviewed; 54 journals were included in the final analysis. Gender and race/ethnicity were determined based on publicly available data for Editor-in-Chief (EiC) and Second-in-Command (SiC) (including deputy, senior, or associate editors). Descriptive statistics and chi-squared were estimated. In the second phase of the study, editors were emailed a 4-item survey to self-identify their demographics.

Results
Out of 793 editorial board members, 72.6% were men and 27.4% were women. Editorial leadership were non-Hispanic white (71.1%) with Asian editorial board members representing the second largest majority at 22.5%. Women comprised only 15.9% of the EiC positions (90% White and 10% Asian). Women were about half as likely to be in the EiC position compared with men [pOR 0.47 (95% CI, 0.23-0.95, P = .03)]. Women represented 28.3% of SiC editorial positions. Surgical oncology had the lowest female representation at 2.3%.

Conclusion
Women and minorities are significantly underrepresented in leadership roles on Editorial Boards in hematology/oncology journals. Importantly, the representation of minority women physicians in EiC positions is at an inexorable zero.
Clinical Outcomes of Afatinib Versus Osimertinib in Patients With Non-Small Cell Lung Cancer With Uncommon EGFR Mutations: A Pooled Analysis
Authors: Wang Chunsheng , Zhao Kewei , Hu Shanliang , Dong Wei , Gong Yan , Xie Conghua 
Published: April 2023

Abstract

Background
The purpose of this analysis was to investigate the effectiveness of afatinib compared to that of osimertinib in patients with non-small cell lung cancer (NSCLC) who harbored uncommon epidermal growth factor receptor (EGFR) mutations.

Methods
A PubMed database-based literature review was conducted to retrieve related studies. Patients harboring EGFR mutations besides the deletion in exon 19 (19del) and point mutation of L858R were included in this analysis. The primary outcome events were the objective response rate (ORR) and progression-free survival (PFS). Propensity score matching (PSM) at a ratio of 1:1 was used between afatinib and osimertinib groups to control the confounding factors. Uncommon EGFR mutations were categorized into 4 groups: insertion in exon 20 (ex20ins), non-ex20ins single uncommon EGFR mutations, compound EGFR mutations that with 19del or L858R, and compound EGFR mutations without 19del or L858R.

Results
After PSM, 71 patients in either the afatinib or osimertinib group were matched. The afatinib group had an ORR of 60.6%, slightly higher than the osimertinib group’s (50.3%), the difference was not statistically significant (P = .610). However, the afatinib group showed a significantly superior PFS benefit than the osimertinib group (11.0 vs. 7.0 months, P = .044). In addition, patients harboring non-ex20ins single uncommon EGFR mutations yield the best ORR and PFS, following treatment of either afatinib (ORR: 76.7%, mPFS: 14.1 months) or osimertinib (ORR: 68.8%, mPFS: 15.1 months). Moreover, there was no significant difference in terms of ORR or PFS between the cohort of patients treated with afatinib or osimertinib, regardless of whether or not the patients had brain metastases.

Conclusions
Both afatinib and osimertinib displayed favorable clinical activities toward uncommon EGFR mutations. Afatinib showed a more profound and durable PFS benefit than osimertinib, although no efficacy advantage was observed.
District Variation in Party System Competition and Women’s Candidacy in Proportional Representation Systems
Authors: Wuthrich F Michael , Albayrak Çağıl 
Published: April 2023

Abstract
This article examines the influence of district-level party system dynamics on the list placement of women candidates. As local district competitive realities change, the strategic considerations for party leaders regarding the selection of non-mainstream political candidate profiles vary in important ways. We measure these dynamics with a set of novel variables that better capture variation in competition from district to district: individual party magnitude, district dominance and district contagion. Turkey’s lower level of party system nationalisation between 2002 and 2018 offers a useful case for such an investigation, and results reveal both the significance and pattern of influence on women candidates for all three strategic variables.
Community policing and COVID-19 management: Household duties of street-level enforcers in Taiwan
Authors: Chen Pei-Shih , Tsai Ting-Jung , Ho Lawrence Ka-Ki 
Published: April 2023

Abstract
Taiwan has been a few of the exceptions recording very low infection figures in the worldwide pandemic COVID-19 since early 2020. The island was regarded as ‘abnormally normal’ during the public health crisis. This study analysed the management of COVID-19 in two cities in Taiwan—Taipei City and New Taipei City, by exploring the roles of two groups of easily forgotten, street-level personnel who were indispensable—the village chiefs and police constables in field stations. We argued the effectiveness of infection control could partly be explained by the well-developed community policing practices. A close cooperation among public officers could be seen in the enforcement of home quarantine order for the Taiwan resident returnees in the early days of the anti-pandemic fight. This government–society collegiality in Taiwan is merely a continuation of the institutionalized practice of community policing evolving from the colonial and authoritarian regimes.
Police Legitimacy in Taiwan and Policing COVID-19
Authors: Kuo Shih-ya , Chang Kuang-Ming , Huang Frank Fu-Yuan , Li Yi 
Published: April 2023

Abstract
To tackle the spread of COVID-19 since its outbreak in January 2020, the police have been given additional powers in Taiwan. Studies have consistently revealed that police legitimacy, the belief that the police are trustworthy and allowed to exercise their authority to maintain order, is the main factor determining whether people are willing to cooperate with the police and comply with laws. This paper explores police legitimacy in Taiwan in terms of whether it exists and whether the Taiwanese police have built or damaged their legitimacy during the unprecedented challenges presented by the COVID-19 pandemic. Using the relevant literature, historical events, public opinion survey results, and official crime data, we find that police legitimacy existed before and has continued to exist during the pandemic in Taiwan.
Police Social Capital and the Effectiveness of Emergency Policing in China During COVID-19
Authors: Lin Haiwen , Wu Tong , Liu Hongsong , Kaunert Christian 
Published: April 2023

Abstract
Emergency policing has played a significant role in controlling the spread of COVID-19 in various countries. China is one of the few countries that has successfully controlled the pandemic. What are the factors that determine the effectiveness of emergency policing in China? This study argues that the social capital played a supportive role in emergency policing during COVID-19. Based on the data analysis, we construct a theoretical framework to explain why pandemic control in China has been effective. The effectiveness of the police response to the COVID-19 pandemic in Zhejiang, China, displays the importance of all three types of social capital for emergency policing, including interaction-assisted social capital represented by ‘grid-governance’, technology-driven social capital represented by ‘data sharing’, and service-assisted social capital represented by ‘safety construction’.
Truth and Bias, Left and Right: Testing Ideological Asymmetries with a Realistic News Supply
Authors: Clemm von Hohenberg Bernhard 
Published: April 2023

Abstract
The debate around “fake news” has raised the question of whether liberals and conservatives differ, first, in their ability to discern true from false information, and second, in their tendency to give more credit to information that is ideologically congruent. Typical designs to measure these asymmetries select, often arbitrarily, a small set of news items as experimental stimuli without clear reference to a “population of information.” This pre-registered study takes an alternative approach by, first, conceptualizing estimands in relation to all political news. Second, to represent this target population, it uses a set of 80 randomly sampled items from a large collection of articles from Google News and three fact-checking sites. In a subsequent survey, a quota sample of US participants (n = 1,393) indicate whether they believe the news items to be true. Conservatives are less truth-discerning than liberals, but also less affected by the congruence of news.
Overcomplete tomography: a novel approach to imaging
Authors: Turunçtur Buse , Valentine Andrew , Sambridge Malcolm 
Published: April 2023

AbstractRegularized least-squares tomography offers a straightforward and efficient imaging method and has seen extensive application across various fields. However, it has a few drawbacks, such as (i) the regularization imposed during the inversion tends to give a smooth solution, which will fail to reconstruct a multi-scale model well or detect sharp discontinuities, (ii) it requires finding optimum control parameters, and (iii) it does not produce a sparse solution. This paper introduces ‘overcomplete tomography’, a novel imaging framework that allows high-resolution recovery with relatively few data points. We express our image in terms of an overcomplete basis, allowing the representation of a wide range of features and characteristics. Following the insight of ‘compressive sensing’, we regularize our inversion by imposing a penalty on the L1 norm of the recovered model, obtaining an image that is sparse relative to the overcomplete basis. We demonstrate our method with a synthetic and a real X-ray tomography example. Our experiments indicate that we can reconstruct a multi-scale model from only a few observations. The approach may also assist interpretation, allowing images to be decomposed into (for example) ‘global’ and ‘local’ structures. The framework presented here can find application across a wide range of fields, including engineering, medical and geophysical tomography.