bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identifying the Effect of Election Closeness on Voter Turnout: Evidence from Swiss Referenda
Authors: Bursztyn Leonardo , Cantoni Davide , Funk Patricia , Schönenberger Felix , Yuchtman Noam 
Published: June 2023

Abstract
We provide evidence of a causal effect of anticipated election closeness on voter turnout, exploiting the precise day-level timing of the release of Swiss national poll results for high-stakes federal referenda, and a novel dataset on daily mail-in voting for the canton of Geneva. Using an event study design, we find that the release of a closer poll causes voter turnout to sharply rise immediately after poll release, with no differential pre-release turnout levels or trends. We provide evidence that polls affect turnout by providing information shaping beliefs about closeness. The effects of close polls are the largest where newspapers report on them most; and, the introduction of polls had significantly larger effects in politically unrepresentative municipalities, where locally available signals of closeness are less correlated with national closeness. We then provide evidence that the effect of close polls is heterogeneous, with an asymmetric effect leading to a higher vote share for the underdog. The effect sizes we estimate are large enough to flip high-stakes election outcomes under plausible counterfactual scenarios.
Fungi as a source of eumelanin: current understanding and prospects
Authors: Beeson William , Gabriel Kyle , Cornelison Christopher 
Published: June 2023

Abstract
Melanins represent a diverse collection of pigments with a variety of structures and functions. One class of melanin, eumelanin, is recognizable to most as the source of the dark black color found in cephalopod ink. Sepia officinalis is the most well-known and sought-after source of non-synthetic eumelanin, but its harvest is limited by the availability of cuttlefish, and its extraction from an animal source brings rise to ethical concerns. In recent years, these limitations have become more pressing as more applications for eumelanin are developed—particularly in medicine and electronics. This surge in interest in the applications of eumelanin has also fueled a rise in the interest of alternative, bio-catalyzed production methods. Many culinarily-utilized fungi are ideal candidates in this production scheme, as examples exist which have been shown to produce eumelanin, their growth at large scales is well understood, and they can be cultivated on recaptured waste streams. However, much of the current research on the fungal production of eumelanin focuses on pathogenic fungi and eumelanin's role in virulence. In this paper, we will review the potential for culinary fungi to produce eumelanin and provide suggestions for new research areas that would be most impactful in the search for improved fungal eumelanin producers.
Deconstructing the latitudinal diversity gradient of North American mammals by nominal order
Authors: Meltesen Kirsten M , Whiting Evan T , Pinto-Ledezma Jesús N , Cicak Tessa S , Fox David L 
Published: June 2023

Abstract
North American mammals follow a well-established latitudinal diversity gradient in species richness. However, the degree to which species in different mammal clades follow the same latitudinal gradient—and to which each clade contributes to the pattern observed for all mammals remains unknown. Here, we separate the overall mammalian latitudinal diversity gradient by mammal orders and investigate the impact of climate and topography on the distribution of each major mammal clade. We joined an equal-area grid (100 × 100 km cells) of continental North America embedded with environmental variables (n = 10) with mammalian species ranges (n = 753). We used spatial regression models to quantify the relationship between species richness and latitude for all mammals, all mammals excluding select clades, and for each individual subordinate clade (n = 9). We used multiple linear regression and simultaneous autoregressive regression models to determine which environmental variables best explained patterns of species richness for each mammal order. Whereas North American mammals altogether exhibit a strong latitudinal diversity gradient in species richness, most orders deviate from the species richness pattern observed for all mammals and their gradients are weak or entirely absent. Bats (Chiroptera) exhibit the strongest latitudinal gradient—their removal from the pattern for all mammals substantially weakens the total mammalian gradient, more so than when rodents are removed. Environmental variables explain patterns of species richness well for some clades, but poorly for others. The gradient we observe for North American mammals today is likely a combined product of multiple diversification events, dispersals, and climatic and tectonic histories.
Case Report: Vision-Threatening Fungal Keratitis in a Service Member Stationed at Guantanamo Bay
Authors: Lambert Lester H , Finger Gabriella E , Tompkins Brett L 
Published: June 2023

ABSTRACT
Fungal keratitis is a major cause of corneal blindness worldwide. Compared to other types of infectious keratitis, fungal keratitis has a relatively poor prognosis because of various factors such as delayed patient presentation and diagnosis. Although associated in earlier studies with poverty and low socioeconomic status, military personnel stationed in tropical and subtropical climates, in low-resource settings, are at risk. Here, we report a case of a 20-year-old active duty contact lens–wearing military service member stationed at Guantanamo Bay who developed a severe vision-threatening fungal keratitis in her left eye. Enhancing health and safety precautions in at-risk settings, maintaining vigilance, and leveraging new imaging modalities will be important to ensure early recognition and treatment.
Numerical simulations of polarisation in gamma-ray burst afterglows
Authors: Covarrubias Rogelio Medina , De Colle Fabio , Urrutia Gerardo , Vargas Felipe 
Published: June 2023

Abstract
We compute the linear polarisation during the afterglow phase of gamma-ray bursts, for both on-axis and off-axis observers. We use numerical simulations of the deceleration of a relativistic jet, and compute the polarisation by post-processing the results of the numerical simulations. In our simulations, we consider a magnetic field that is chaotic in the plane of the shock, in addition to a magnetic field component that is parallel to the shock velocity. While the linear polarisation computed for on-axis observers is consistent with previous analytical estimates, we found that lateral expansion, which is accurately handled in our simulations, plays a crucial role in determining the linear polarisation for off-axis observers. Our results show that the off-axis linear polarisation, as seen by off-axis observers, exhibits a single peak, in contrast to the two peaks inferred by previous analytical studies. The maximum polarisation degree is 40 per cent at an observing angle θobs = 0.4 rad, and it decreases as the observing angle increases, which is opposite to what predicted by analytical models, where polarisation increases with larger observing angles. From the upper limit of 12 per cent in the linear polarisation obtained at 244 days for the GRB 170817A, we also infer an anisotropy factor of B∥/B⊥ = 0.5 − 0.9, consistent with the post-shock magnetic field being amplified by turbulence.
New constraints on the kinematic, relativistic, and evolutionary properties of the PSR J1757−1854 double neutron star system
Authors: Cameron A D , Bailes M , Champion D J , Freire P C C , Kramer M , McLaughlin M A , Ng C , Possenti A , Ridolfi A , Tauris T M , Wahl H M , Wex N 
Published: June 2023

ABSTRACT
PSR J1757−1854 is one of the most relativistic double neutron star binary systems known in our Galaxy, with an orbital period of $P_\text{b}=4.4\, \text{h}$ and an orbital eccentricity of e = 0.61. As such, it has promised to be an outstanding laboratory for conducting tests of relativistic gravity. We present the results of a 6-yr campaign with the 100-m Green Bank and 64-m Parkes radio telescopes, designed to capitalize on this potential. We identify secular changes in the profile morphology and polarization of PSR J1757−1854, confirming the presence of geodetic precession and allowing the constraint of viewing geometry solutions consistent with General Relativity. We also update PSR J1757−1854’s timing, including new constraints of the pulsar’s proper motion, post-Keplerian parameters, and component masses. We conclude that the radiative test of gravity provided by PSR J1757−1854 is fundamentally limited to a precision of 0.3 per cent due to the pulsar’s unknown distance. A search for pulsations from the companion neutron star is also described, with negative results. We provide an updated evaluation of the system’s evolutionary history, finding strong support for a large kick velocity of $w\ge 280\, \rm{km\,s}^{-1}$ following the second progenitor supernova. Finally, we reassess PSR J1757−1854’s potential to provide new relativistic tests of gravity. We conclude that a 3-σ constraint of the change in the projected semimajor axis ($\dot{x}$) associated with Lense–Thirring precession is expected no earlier than 2031. Meanwhile, we anticipate a 3-σ measurement of the relativistic orbital deformation parameter δθ as soon as 2026.
Atmospheric recycling of volatiles by pebble-accreting planets
Authors: Wang Yu , Ormel Chris W , Huang Pinghui , Kuiper Rolf 
Published: June 2023

ABSTRACT
Planets, embedded in their natal discs, harbour hot envelopes. When pebbles are accreted by these planets, the contained volatile components may sublimate, enriching the envelope and potentially changing its thermodynamical properties. However, the envelopes of embedded planets actively exchange material with the disc, which would limit the buildup of a vapour-rich atmosphere. To properly investigate these processes, we have developed a new phase change module to treat the sublimation process with hydrodynamical simulations. Combined with the recently developed multidust fluid approach, we conduct 2D self-consistent hydrodynamic simulations to study how pebble sublimation influences the water content of super-Earths and sub-Neptunes. We find the extent and the amount of vapour that a planet is able to hold on to is determined by the relative size of the sublimation front and the atmosphere. When the sublimation front lies far inside the atmosphere, vapour tends to be locked deep in the atmosphere and keeps accumulating through a positive feedback mechanism. On the other hand, when the sublimation front exceeds the (bound) atmosphere, the ice component of incoming pebbles can be fully recycled and the vapour content reaches a low, steady value. Low disc temperature, small planet mass, and high pebble flux (omitting accretion heating by pebbles) render the planet atmosphere vapour-rich while the reverse changes render it vapour-poor. The phase change module introduced here can in future studies also be employed to model the chemical composition of the gas in the vicinity of accreting planets and around snowlines.
On the origin of the anomalous gas, non-declining rotation curve, and disc asymmetries in NGC 253
Authors: Lyu Xuanyi , Westmeier T , Meurer Gerhardt R , Hanish D J 
Published: June 2023

ABSTRACT
We present a multiwavelength (from far-ultraviolet to ${\rm H}\, \rm {\small I}$ emission) study of star formation feedback on the kinematics of the interstellar medium in the Sculptor galaxy, NGC 253. Its three well-known features (a disrupted stellar disc, a previously reported declining rotation curve, and anomalous ${\rm H}\, \rm {\small I}$ gas) are studied in a common context of disc asymmetries. About 170 h of on-source ATCA observations are collected and reduced into two versions of ${\rm H}\, \rm {\small I}$ data cubes of different angular resolution (30 arcsec/2 arcmin) and H i column density sensitivity (7.4 × 1019 cm−2/4 × 1018 cm−2). We separate the anomalous gas from the disc using a custom-made line profile fitting toolkit called FMG. Two star formation tracers (H α, FUV emission) are carefully processed and studied. We find that at R &gt; 7.5 kpc, the star formation activity is strongly lopsided (SFRNE &gt; SFRSW), and investigate several other properties (H α/FUV, dust temperature, stellar age, and disc stability parameters). We also find that the declining nature of the rotation curve perceived by previous studies is not intrinsic but a combined effect of kinematical asymmetries at R = 7.5–16 kpc. This is likely the consequence of star formation triggered outflow. The mass distribution and the time-scale of the anomalous gas also imply that it originates from gas outflow, which is perhaps caused by galaxy–galaxy interaction considering the crowded environment of NGC 253.
Distinct polarization properties for two emission states of four pulsars
Authors: Yan Yi , Wang P F , Han J L 
Published: June 2023

ABSTRACT
Four pulsars, PSRs J1838+1523, J1901+0510, J1909+0007, and J1929+1844, are found to exhibit bright and weak emission states from sensitive observations made using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). New FAST observations have measured the polarization properties for the two states, and reveal that the polarization profiles, linear polarization percentage, and polarization position angle curves, as well as circular polarization percentage, are partially or entirely different in the two emission states. Remarkably, PSR J1838+1523 has very different slopes for the polarization position angle curves. PSR J1901+0510 has a wider profile and a higher linear polarization in the weak state than in the bright state. PSR J1909+0007 has very distinct polarization angle curves for the two modes. While in the case of PSR J1929+1844, the central profile component evolves with frequency in the bright state, and the senses of circular polarization are opposite in the two modes. The different polarization properties of the two emission states provide valuable insights into the physical processes and emission conditions in the pulsar magnetosphere.
The MillenniumTNG project: intrinsic alignments of galaxies and haloes
Authors: Delgado Ana Maria , Hadzhiyska Boryana , Bose Sownak , Springel Volker , Hernquist Lars , Barrera Monica , Pakmor Rüdiger , Ferlito Fulvio , Kannan Rahul , Hernández-Aguayo César , White Simon D M , Frenk Carlos 
Published: June 2023

ABSTRACT
The intrinsic alignment (IA) of observed galaxy shapes with the underlying cosmic web is a source of contamination in weak lensing surveys. Sensitive methods to identify the IA signal will therefore need to be included in the upcoming weak lensing analysis pipelines. Hydrodynamical cosmological simulations allow us to directly measure the intrinsic ellipticities of galaxies, and thus provide a powerful approach to predict and understand the IA signal. Here we employ the novel, large-volume hydrodynamical simulation MTNG740, a product of the MillenniumTNG (MTNG) project, to study the IA of galaxies. We measure the projected correlation functions between the intrinsic shape/shear of galaxies and various tracers of large-scale structure, w+g, w+m, w++ over the radial range $r_{\rm p} \in [0.02 , 200]\, h^{-1}{\rm Mpc}$ and at redshifts z = 0.0, 0.5, and 1.0. We detect significant signal-to-noise IA signals with the density field for both elliptical and spiral galaxies. We also find significant intrinsic shear–shear correlations for ellipticals. We further examine correlations of the intrinsic shape of galaxies with the local tidal field. Here we find a significant IA signal for elliptical galaxies assuming a linear model. We also detect a weak IA signal for spiral galaxies under a quadratic tidal torquing model. Lastly, we measure the alignment between central galaxies and their host dark-matter haloes, finding small to moderate misalignments between their principal axes that decline with halo mass.
Double neutron star formation via consecutive type II supernova explosions
Authors: Fröhlich Viktória , Regály Zsolt , Vinkó József 
Published: June 2023

ABSTRACT
Since the discovery of the first double neutron star (DNS) system, the number of these exotic binaries has reached 15. Here we investigate a channel of DNS formation in binary systems with components above the mass limit of Type II supernova explosion (SN II), that is, 8M⊙. We apply a spherically symmetric homologous envelope expansion model to account for mass-loss, and follow the dynamical evolution of the system numerically with a high-precision integrator. The first SN occurs in a binary system whose orbital parameters are pre-defined, then, the homologous expansion model is applied again in the newly formed system. Analysing 1 658 880 models we find that DNS formation via subsequent SN II explosions requires a fine-tuning of the initial parameters. Our model can explain DNS systems with a separation greater than 2.95 au. The eccentricity of the DNS systems spans a wide range thanks to the orbital circularization effect due to the second SN II explosion. The eccentricity of the DNS is sensitive to the initial eccentricity of the binary progenitor and the orbital position of the system preceding the second explosion. In agreement with the majority of the observations of DNS systems, we find the system centre-of-mass velocities to be less than 60 km s−1. Neutron stars that become unbound in either explosion gain a peculiar velocity in the range of 0.02 − 240 km s−1. In our model, the formation of tight DNS systems requires a post-explosion orbit-shrinking mechanism, possibly driven by the ejected envelopes.
2.5D magnetohydrodynamic models of circumstellar discs around FS CMa post-mergers – I. Non-stationary accretion stage
Authors: Moranchel-Basurto A , Korčáková D , Chametla R O 
Published: June 2023

ABSTRACT
We investigate the dynamic evolution of the gaseous regions around FS CMa post-mergers. Owing to the slow rotation of the central B-type star, the dynamics is driven mainly by the magnetic field of the central star. Recent observations have allowed us to set realistic initial conditions, such as the magnetic field value ($B_\star \approx 6\times 10^{3}\, \mathrm{G}$), the mass of the central star ($M_\star =6\, \mathrm{M}_\odot$), and the initial disc density $\rho _{d0}\in [10^{-13}\, \mathrm{g\, cm^{-3}},10^{-11}\, \mathrm{g \, cm^{-3}}]$. We use the pluto code to perform 2.5D magnetohydrodynamic simulations of thin and thick disc models. Especially relevant for the interpretation of the observed properties of FS CMa post-mergers are the results for low-density discs, in which we find a jet emerging from the inner edge of the disc, as well as the formation of the so-called ‘hot plasmoid’ in the coronal region. Jets are probably detected as discrete absorption components in the resonance lines of FS CMa stars. Moreover, the magnetic field configuration in the low-density plasma region favours the appearance of magnetocentrifugal winds from the disc. The currents towards the star created by the magnetic field may explain accidentally observed material infall. The disc structure is significantly changed owing to the presence of the magnetic field. The magnetic field is also responsible for the formation of a hot corona, as observed in several FS CMa stars through the Raman lines. Our results are valid for all magnetic stars surrounded by a low-density plasma, that is, by some stars showing the B[e] phenomenon.
The breakdown of current gyrochronology as evidenced by old coeval stars
Authors: Silva-Beyer Joaquín , Godoy-Rivera Diego , Chanamé Julio 
Published: June 2023

ABSTRACT
Gyrochronology can yield useful ages for field main-sequence stars, a regime where other techniques are problematic. Typically, gyrochronology relations are calibrated using young (≲2 Gyr) clusters, but the constraints at older ages are scarce, making them potentially inaccurate and imprecise. In order to test the performance of existing relations, we construct samples of stellar pairs with coeval components, for a range of ages and with available rotation periods. These include randomly paired stars in clusters, and wide binaries in the Kepler field. We design indicators that, based on the measured rotation periods and expectations from gyrochronology, quantify the (dis)agreement between the coeval pairs and the gyrochronology calibrations under scrutiny. Our results show that wide binaries and cluster members are in better concordance with gyrochronology than samples of randomly paired field stars, confirming that the relations have predicting power. However, the agreement with the examined relations decreases for older stars, revealing a degradation of the examined relations with age, in agreement with recent works. This highlights the need for novel empirical constraints at older ages that may allow revised calibrations. Notably, using coeval stars to test gyrochronology poses the advantage of circumventing the need for age determinations while simultaneously exploiting larger samples at older ages. Our test is independent of any specific age–rotation relation, and it can be used to evaluate future spin-down models. In addition, taking gyrochronology at face value, we note that our results provide new empirical evidence that the components of field wide binaries are indeed coeval.
Born this way: thin disc, thick disc, and isotropic spheroid formation in FIRE-2 Milky Way–mass galaxy simulations
Authors: Yu Sijie , Bullock James S , Gurvich Alexander B , Hafen Zachary , Stern Jonathan , Boylan-Kolchin Michael , Faucher-Giguère Claude-André , Wetzel Andrew , Hopkins Philip F , Moreno Jorge 
Published: June 2023

ABSTRACT
We investigate the formation of Milky Way–mass galaxies using FIRE-2 ΛCDM cosmological zoom-in simulations by studying the orbital evolution of stars formed in the main progenitor of the galaxy, from birth to the present day. We classify in situ stars as isotropic spheroid, thick-disc, and thin-disc according to their orbital circularities and show that these components are assembled in a time-ordered sequence from early to late times, respectively. All simulated galaxies experience an early phase of bursty star formation that transitions to a late-time steady phase. This transition coincides with the time that the inner CGM virializes. During the early bursty phase, galaxies have irregular morphologies and new stars are born on radial orbits; these stars evolve into an isotropic spheroidal population today. The bulk of thick-disc stars form at intermediate times, during a clumpy-disc ‘spin-up’ phase, slightly later than the peak of spheroid formation. At late times, once the CGM virializes and star formation ‘cools down,’ stars are born on circular orbits within a narrow plane. Those stars mostly inhabit thin discs today. Broadly speaking, stars with disc-like or spheroid-like orbits today were born that way. Mergers on to discs and secular processes do affect kinematics in our simulations, but play only secondary roles in populating thick-disc and in situ spheroid populations at z = 0. The age distributions of spheroid, thick disc, and thin disc populations scale self-similarly with the steady-phase transition time, which suggests that morphological age dating can be linked to the CGM virialization time in galaxies.