bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decreasing Incidence of Estrogen Receptor–Negative Breast Cancer in the United States: Trends by Race and Region
Authors: Davis Lynn Brittny C , Chernyavskiy Pavel , Gierach Gretchen L , Rosenberg Philip S 
Published: September 2021

Abstract

Background
Incidence of estrogen receptor (ER)-negative breast cancer, an aggressive subtype, is highest in US African American women and in Southern residents but has decreased overall since 1992. We assessed whether ER-negative breast cancer is decreasing in all age groups and cancer registries among non-Hispanic White (NHW), non-Hispanic Black (NHB), and Hispanic White (HW) women.

Methods
We analyzed 17 Surveillance, Epidemiology, and End-Results (SEER) Program registries (12 for 1992-2016; 5 for 2000-2016) to assess NHW, NHB, and HW trends by ER status and age group (30-39 years, 40-49 years, 50-69 years, 70-84 years). We used hierarchical age-period-cohort models that account for sparse data, which improve estimates to quantify between-registry heterogeneity in mean incidence rates and age-adjusted trends vs SEER overall.

Results
Overall, ER-negative incidence was highest in NHB, then NHW and HW women, and decreased from 1992-2016 in each age group and racial or ethnic group. The greatest decrease was for HW women aged 40-49 years, with an annual percent change of –3.5%/y (95% credible interval = −4.4%, −2.7%) averaged over registries. The trend heterogeneity was statistically significant in every race or ethnic and age group. Furthermore, the incidence relative risks by race or ethnicity compared with the race-specific SEER average were also statistically significantly heterogeneous across the majority of registries and age groups (62 of 68 strata). The greatest heterogeneity was seen in HW women, followed by NHB women, and the least in NHW women.

Conclusions
Decreasing ER-negative breast cancer incidence differs meaningfully by US region and age among NHB and HW women. Analytical studies including minority women from higher and lower incidence areas may provide insights into breast cancer racial disparities.
Shoring up economic refugees: Venezuelan migrants in the Ecuadoran labor market
Authors: Olivieri Sergio , Ortega Francesc , Rivadeneira Ana , Carranza Eliana 
Published: September 2021

Abstract
Ecuador became the third largest receiver of the 4.3 million Venezuelans who left their country in the last five years, hosting around 10 per cent of them. Little is known about the characteristics of these migrants and their labor market outcomes. This article fills this gap by analyzing a new large survey (EPEC). On average, Venezuelan workers are highly skilled and have high rates of employment, compared with Ecuadorans. However, their employment is of much lower quality, characterized by low wages, and high rates of informality and temporality. Venezuelans have experienced significant occupational downgrading, relative to their employment prior to emigration. As a result, despite their high educational attainment, Venezuelans primarily compete for jobs with the least skilled and more economically vulnerable Ecuadoran workers. Our simulations suggest that measures that allow Venezuelans to obtain employment that matches their skills, such as facilitating the conversion of education credentials, would increase Ecuador’s GDP between 1.6 and 1.9 per cent and alleviate the pressure on disadvantaged native workers. We also show that providing work permits to Venezuelan workers would substantially reduce their rates of informality and increase their average earnings.
When outliers are different
Authors: Katz J I 
Published: September 2021

ABSTRACT
When does the presence of an outlier in some measured property indicate that the outlying object differs qualitatively, rather than quantitatively, from other members of its apparent class? Historical astronomical examples include the many types of supernovae and short versus long gamma-ray bursts. A qualitative difference implies that some parameter has a characteristic scale, and hence its distribution cannot be a power law (that can have no such scale). If the distribution is a power law, the objects differ only quantitatively. The applicability of a power law to an empirical distribution may be tested by comparing the most extreme member to its next-most extreme. The probability distribution of their ratio is calculated, and compared to data for stars, radio and X-ray sources, and the fluxes, fluences, and rotation measures of fast radio bursts (FRBs). It is found with high statistical significance that the giant outburst of soft gamma repeater SGR 1806-20 differed qualitatively from its lesser outbursts and FRB 200428 differed qualitatively from other FRBs (by location in the Galaxy), but that in some supernova remnant models of rotation measure FRB 121102 is not, statistically significantly, an outlier.
Meteor shower radiant dispersions in Global Meteor Network data
Authors: Moorhead Althea V , Clements Tiffany , Vida Denis 
Published: September 2021

ABSTRACT
Meteor showers occur when streams of meteoroids originating from a common source intersect the Earth. There will be small dissimilarities between the direction of motion of different meteoroids within a stream, and these small differences will act to broaden the radiant, or apparent point of origin, of the shower. This dispersion in meteor radiant can be particularly important when considering the effect of the Earth’s gravity on the stream, as it limits the degree of enhancement of the stream’s flux due to gravitational focusing. In this paper, we present measurements of the radiant dispersion of 12 showers using observations from the Global Meteor Network. We find that the median offset of individual meteors from the shower radiant ranges from 0.32○ for the eta Aquariids to 1.41○ for the Southern Taurids. We also find that there is a small but statistically significant drift in Sun-centred ecliptic radiant and/or geocentric speed over time for most showers. Finally, we compare radiant dispersion with shower duration and find that, in contrast with previous results, the two quantities are not correlated in our data.
The GOGREEN survey: transition galaxies and the evolution of environmental quenching
Authors: McNab Karen , Balogh Michael L , van der Burg Remco F J , Forestell Anya , Webb Kristi , Vulcani Benedetta , Rudnick Gregory , Muzzin Adam , Cooper M C , McGee Sean , Biviano Andrea , Cerulo Pierluigi , Chan Jeffrey C C , De Lucia Gabriella , Demarco Ricardo , Finoguenov Alexis , Forrest Ben , Golledge Caelan , Jablonka Pascale , Lidman Chris , Nantais Julie , Old Lyndsay , Pintos-Castro Irene , Poggianti Bianca , Reeves Andrew M M , Wilson Gillian , Yee Howard K C , Zaritsky Dennis 
Published: September 2021

ABSTRACT
We measure the rate of environmentally driven star formation quenching in galaxies at z ∼ 1, using eleven massive ($M\approx 2\times 10^{14}\, \mathrm{M}_\odot$) galaxy clusters spanning a redshift range 1.0 &lt; z &lt; 1.4 from the GOGREEN sample. We identify three different types of transition galaxies: ‘green valley’ (GV) galaxies identified from their rest-frame (NUV − V) and (V − J) colours; ‘blue quiescent’ (BQ) galaxies, found at the blue end of the quiescent sequence in (U − V) and (V − J) colour; and spectroscopic post-starburst (PSB) galaxies. We measure the abundance of these galaxies as a function of stellar mass and environment. For high-stellar mass galaxies (log M/M⊙ &gt; 10.5) we do not find any significant excess of transition galaxies in clusters, relative to a comparison field sample at the same redshift. It is likely that such galaxies were quenched prior to their accretion in the cluster, in group, filament, or protocluster environments. For lower stellar mass galaxies (9.5 &lt; log M/M⊙ &lt; 10.5) there is a small but significant excess of transition galaxies in clusters, accounting for an additional ∼5–10 per cent of the population compared with the field. We show that our data are consistent with a scenario in which 20–30 per cent of low-mass, star-forming galaxies in clusters are environmentally quenched every Gyr, and that this rate slowly declines from z = 1 to z = 0. While environmental quenching of these galaxies may include a long delay time during which star formation declines slowly, in most cases this must end with a rapid (τ &lt; 1 Gyr) decline in star formation rate.
Progenitor-mass-dependent yields amplify intrinsic scatter in dwarf-galaxy elemental abundance ratios
Authors: Muley Dhruv A , Wheeler Coral R , Hopkins Philip F , Wetzel Andrew , Emerick Andrew , Kereš Dušan 
Published: September 2021

ABSTRACT
We explore the effect of including progenitor mass- and metallicity-dependent yields, supernova rates and energetics on variations in elemental abundance ratios (particularly [α/Fe]) in dwarf galaxies. To understand how the scatter and overall trends in [α/Fe] are affected by including variable metal yields from a discretely sampled initial mass function, we run FIRE simulations of a dwarf galaxy (M⋆(z = 0$) \sim 10^6\rm \, M_{\odot })$ using nucleosynthetic yields from the NuGrid data base that depend on the stellar progenitor mass and metallicity. While NuGrid exhibits lower aggregate α-element production than default FIRE yields, we find that its explicit mass dependence, even when including turbulent metal diffusion, substantially widens the intrinsic scatter in the simulated [Fe/H]-[α/Fe] – a phenomenon visible in some observations of dwarf galaxies.
Dynamical stability of giant planets: the critical adiabatic index in the presence of a solid core
Authors: Kundu Suman Kumar , Coughlin Eric R , Youdin Andrew N , Armitage Philip J 
Published: September 2021

ABSTRACT
The dissociation and ionization of hydrogen, during the formation of giant planets via core accretion, reduce the effective adiabatic index γ of the gas and could trigger dynamical instability. We generalize the analysis of Chandrasekhar, who determined that the threshold for instability of a self-gravitating hydrostatic body lies at γ = 4/3, to account for the presence of a planetary core, which we model as an incompressible fluid. We show that the dominant effect of the core is to stabilize the envelope to radial perturbations, in some cases completely (i.e. for all γ &gt; 1). When instability is possible, unstable planetary configurations occupy a strip of γ values whose upper boundary falls below γ = 4/3. Fiducial evolutionary tracks of giant planets forming through core accretion appear unlikely to cross the dynamical instability strip that we define.
Nitrogen evolution in the halo, thick disc, thin disc, and bulge of the Galaxy
Authors: Grisoni V , Matteucci F , Romano D 
Published: September 2021

ABSTRACT
We study the evolution of nitrogen (N) in the Galactic halo, thick disc, thin disc, and bulge by comparing detailed chemical evolution models with recent observations. The models used in this work have already been constrained to explain the abundance patterns of α-elements and the metallicity distribution functions of halo, disc, and bulge stars; here, we adopt them to investigate the origin and evolution of N in the different Galactic components. First, we consider different sets of yields and study the importance of the various channels proposed for N production. Secondly, we apply the reference models to study the evolution of both the Galactic discs and bulge. We conclude that: i) primary N produced by rotating massive stars is required to reproduce the plateau in log(N/O) and [N/Fe] ratios at low metallicity, as well as the secondary and primary production from low- and intermediate-mass stars to reproduce the data of the thin disc; ii) the parallel model can provide a good explanation of the evolution of N abundance in the thick and thin discs, and we confirm that the thick disc has evolved much faster than the thin disc, in agreement with the results from the abundance patterns of other chemical elements; and iii) finally, we present new model predictions for N evolution in the Galactic bulge, and we show that the observations in bulge stars can be explained if massive stars rotate fast during the earliest phases of Galactic evolution, in agreement with findings from the abundance pattern of carbon.
Resolving local and global kinematic signatures of satellite mergers with billion particle simulations
Authors: Hunt Jason A S , Stelea Ioana A , Johnston Kathryn V , Gandhi Suroor S , Laporte Chervin F P , Bédorf Jeroen 
Published: September 2021

ABSTRACT
In this work, we present two new ∼109 particle self-consistent simulations of the merger of a Sagittarius-like dwarf galaxy with a Milky Way (MW)-like disc galaxy. One model is a violent merger creating a thick disc, and a Gaia–Enceladus/Sausage-like remnant. The other is a highly stable disc which we use to illustrate how the improved phase space resolution allows us to better examine the formation and evolution of structures that have been observed in small, local volumes in the MW, such as the z−vz phase spiral and clustering in the vR−vϕ plane when compared to previous works. The local z−vz phase spirals are clearly linked to the global asymmetry across the disc: we find both 2-armed and 1-armed phase spirals, which are related to breathing and bending behaviours, respectively. Hercules-like moving groups are common, clustered in vR−vϕ in local data samples in the simulation. These groups migrate outwards from the inner galaxy, matching observed metallicity trends even in the absence of a galactic bar. We currently release the best-fitting ‘present-day’ merger snapshots along with the unperturbed galaxies for comparison.
Halo cluster shapes: insights from simulated galaxies and ICL with prospects for weak lensing applications
Authors: Gonzalez Elizabeth J , Ragone-Figueroa Cinthia , Donzelli Carlos J , Makler Martín , García Lambas Diego , Granato Gian Luigi 
Published: September 2021

ABSTRACT
We present a detailed study of the shapes and alignments of different galaxy cluster components using hydrodynamical simulations. We compute shape parameters from the dark matter (DM) distribution, the galaxy members and the intracluster light (ICL). We assess how well the DM cluster shape can be constrained by means of the identified galaxy member positions and the ICL. Further, we address the dilution factor introduced when estimating the cluster elongation using weak-lensing stacking techniques, which arises due to the misalignment between the total surface mass distribution and the distribution of luminous tracers. The dilution is computed considering the alignment between the DM and the brightest cluster galaxy, the galaxy members and the ICL. Our study shows that distributions of galaxy members and ICL are less spherical than the DM component, although both are well aligned with the semimajor axis of the latter. We find that the distribution of galaxy members hosted in more concentrated subhaloes is more elongated than the distribution of the DM. Moreover, these galaxies are better aligned with the DM component compared to the distribution of galaxies hosted in less concentrated subhaloes. We conclude that the positions of galaxy members can be used as suitable tracers to estimate the cluster surface density orientation, even when a low number of members is considered. Our results provide useful information for interpreting the constraints on the shapes of galaxy clusters in observational studies.
Assessing the sources of reionization: a spectroscopic case study of a 30× lensed galaxy at z ∼ 5 with Lyα, C iv, Mg ii, and [Ne iii]
Authors: Witstok Joris , Smit Renske , Maiolino Roberto , Curti Mirko , Laporte Nicolas , Massey Richard , Richard Johan , Swinbank Mark 
Published: September 2021

ABSTRACT
We present a detailed spectroscopic analysis of a galaxy at z ≃ 4.88 that is, by chance, magnified ∼30× by gravitational lensing. Only three sources at z ≳ 5 are known with such high magnification. This particular source has been shown to exhibit widespread, high equivalent width ${{\rm C\, \small {IV}}}\ \lambda 1549\, \mathring{\rm A}$ emission, implying it is a unique example of a metal-poor galaxy with a hard radiation field, likely representing the galaxy population responsible for cosmic reionization. Using ultraviolet (UV) nebular line ratio diagnostics, Very Large Telescope (VLT)/X-shooter observations rule out strong active galactic nuclei (AGN) activity, indicating a stellar origin of the hard radiation field instead. We present a new detection of ${[{\rm Ne\, \small {III}}]}\ \lambda 3870\, \mathring{\rm A}$ and use the [${\rm Ne\, \small {III}}$]/[${\rm O\, \small {II}}$] line ratio to constrain the ionization parameter and gas-phase metallicity. Closely related to the commonly used [${\rm O\, \small {III}}$]/[${\rm O\, \small {II}}$] ratio, our [${\rm Ne\, \small {III}}$]/[${\rm O\, \small {II}}$] measurement shows this source is similar to local ‘Green Pea’ galaxies and Lyman-continuum leakers. It furthermore suggests this galaxy is more metal poor than expected from the fundamental metallicity relation, possibly as a consequence of excess gas accretion diluting the metallicity. Finally, we present the highest redshift detection of ${{\rm Mg\, \small {II}}}\ \lambda 2796\, \mathring{\rm A}$, observed at high equivalent width in emission, in contrast to more evolved systems predominantly exhibiting ${\rm Mg\, \small {II}}$ absorption. Strong ${\rm Mg\, \small {II}}$ emission has been observed in most z ∼ 0 Lyman-continuum leakers known and has recently been proposed as an indirect tracer of escaping ionizing radiation. In conclusion, this strongly lensed galaxy, observed just $300\, \mathrm{Myr}$ after reionization ends, enables testing of observational diagnostics proposed to constrain the physical properties of distant galaxies in the James Webb Space Telescope (JWST)/Extremely Large Telescope (ELT) era.
Effects of dust particles charged by inelastic collisions and by photoionization on Alfvén waves in a stellar wind
Authors: De Toni L B , Gaelzer R 
Published: September 2021

ABSTRACT
Using a kinetic description of a homogeneous magnetized dusty plasma with Maxwellian distribution of electrons and protons and dust particles charged by inelastic collisions and by photoionization, we analyse the dispersion relation considering the case where waves and radiation propagate exactly parallel to the ambient magnetic field. The investigation emphasizes the changes that the photoionization process brings to the propagation and damping of the waves in a stellar wind environment, since Alfvén waves are believed to play a significant role in the heating and acceleration processes that take place in the wind. The results show that, in the presence of dust with negative equilibrium electrical charge, the Alfvén mode decouples into the whistler and ion cyclotron modes for all values of wavenumber, but when dust particles acquire neutral or positive values of electrical charge, these modes may couple for certain values of wavenumber. It is also seen that the whistler and ion cyclotron modes present null group velocity in an interval of small wavenumber, and that the maximum value of wavenumber for which the waves are non-propagating is reduced in the presence of the photoionization process. For very small values of wavenumber, the damping rates of the modes could change significantly from very small to very high values if the sign of the dust electrical charge is changed.
The search for failed supernovae with the Large Binocular Telescope: a new candidate and the failed SN fraction with 11 yr of data
Authors: Neustadt J M M , Kochanek C S , Stanek K Z , Basinger C , Jayasinghe T , Garling C T , Adams S M , Gerke J 
Published: September 2021

ABSTRACT
We present updated results of the Large Binocular Telescope Search for Failed Supernovae. This search monitors luminous stars in 27 nearby galaxies with a current baseline of 11 yr of data. We re-discover the failed supernova (SN) candidate N6946-BH1 as well as a new candidate, M101-OC1. M101-OC1 is a blue supergiant that rapidly disappears in optical wavelengths with no evidence for significant obscuration by warm dust. While we consider other options, a good explanation for the fading of M101-OC1 is a failed SN, but follow-up observations are needed to confirm this. Assuming only one clearly detected failed SN, we find a failed SN fraction $f = 0.16^{+0.23}_{-0.12}$ at 90 per cent confidence. We also report on a collection of stars that show slow (∼decade), large amplitude (ΔL/L &gt; 3) luminosity changes.
Period-age-metallicity and period-age-colour-metallicity relations for classical Cepheids: an application to the Gaia EDR3 sample
Authors: De Somma Giulia , Marconi Marcella , Cassisi Santi , Ripepi Vincenzo , Pietrinferni Adriano , Molinaro Roberto , Leccia Silvio , Musella Ilaria 
Published: September 2021

ABSTRACT
Based on updated pulsation models for classical Cepheids, computed for various assumptions about the metallicity and helium abundance, roughly representative of pulsators in the Small Magellanic Cloud (Z = 0.004 and Y = 0.25), Large Magellanic Cloud (Z = 0.008 and Y = 0.25), and M31 (Z = 0.03 and Y = 0.28), and self-consistent updated evolutionary predictions, we derived period-age and multi-band period-age-colour relations that also take into account variations in the mass–luminosity (ML) relation. These results, combined with those previously derived for Galactic Cepheids, were used to investigate the metallicity effect when using these variables as age indicators. In particular, we found that a variation in the metal abundance affects both the slope and the zero-point of the above-mentioned relations. The new relations were applied to a sample of Gaia Early Data Release 3 classical Cepheids. The retrieved distribution of the individual ages confirms that a brighter ML relation produces older ages and that first overtone pulsators are found to be concentrated towards older ages with respect to the fundamental ones at a fixed ML relation. Moreover, the inclusion of a metallicity term in the period-age and period-age-colour relations slightly modifies the predicted ages. In particular, the age distribution of the selected sample of Galactic Cepheids is found to be shifted towards slightly older values, when the F-mode canonical relations are considered, with respect to the case at a fixed solar chemical composition. A marginally opposite dependence can be found in the non-canonical F-mode and canonical FO-mode cases.