bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrated mass-loss of evolved stars in M4 using asteroseismology
Authors: Howell Madeline , Campbell Simon W , Stello Dennis , De Silva Gayandhi M 
Published: July 2022

ABSTRACT
Mass-loss remains a major uncertainty in stellar modelling. In low-mass stars, mass-loss is most significant on the red giant branch (RGB), and will impact the star’s evolutionary path and final stellar remnant. Directly measuring the mass difference of stars in various phases of evolution represents one of the best ways to quantify integrated mass-loss. Globular clusters (GCs) are ideal objects for this. M4 is currently the only GC for which asteroseismic data exist for stars in multiple phases of evolution. Using K2 photometry, we report asteroseismic masses for 75 red giants in M4, the largest seismic sample in a GC to date. We find an integrated RGB mass-loss of $\Delta \overline{M} = 0.17 \pm 0.01 ~\mathrm{M}_{\odot }$, equivalent to a Reimers’ mass-loss coefficient of ηR = 0.39. Our results for initial mass, horizontal branch mass, ηR, and integrated RGB mass-loss show remarkable agreement with previous studies, but with higher precision using asteroseismology. We also report the first detections of solar-like oscillations in early asymptotic giant branch (EAGB) stars in GCs. We find an average mass of $\overline{M}_{\text{EAGB}}=0.54 \pm 0.01 ~\mathrm{M}_{\odot }$, significantly lower than predicted by models. This suggests larger-than-expected mass-loss on the horizontal branch. Alternatively, it could indicate unknown systematics in the scaling relations for the EAGB. We discover a tentative mass bimodality in the RGB sample, possibly due to the multiple populations. In our red horizontal branch sample, we find a mass distribution consistent with a single value. We emphasize the importance of seismic studies of GCs since they could potentially resolve major uncertainties in stellar theory.
On the use of galaxies as clocks and the universal expansion
Authors: Ahlström Kjerrgren Anders , Mörtsell Edvard 
Published: July 2022

ABSTRACT
We set out to rederive the 8 Hubble parameter values obtained from estimated relative galaxy ages by Simon et al. We find that to obtain the level of precision claimed in H($\mathit{ z}$), unrealistically small galaxy age uncertainties have to be assumed. Also, some parameter values will be correlated. In our analysis we find that the uncertainties in the Hubble parameter values are significantly larger when 8 independent H($\mathit{ z}$) are obtained using Monte Carlo sampling. Smaller uncertainties can be obtained using Gaussian processes, but at the cost of strongly correlated results. We do not obtain any useful constraints on the Hubble parameter from the galaxy data employed.
A galaxy-driven model of type Ia supernova luminosity variations
Authors: Wiseman P , Vincenzi M , Sullivan M , Kelsey L , Popovic B , Rose B , Brout D , Davis T M , Frohmaier C , Galbany L , Lidman C , Möller A , Scolnic D , Smith M , Aguena M , Allam S , Andrade-Oliveira F , Annis J , Bertin E , Bocquet S , Brooks D , Burke D L , Carnero Rosell A , Carrasco Kind M , Carretero J , Castander F J , Costanzi M , Pereira M E S , Desai S , Diehl H T , Doel P , Everett S , Ferrero I , Friedel D , Frieman J , García-Bellido J , Gatti M , Gaztanaga E , Gruen D , Gschwend J , Gutierrez G , Hinton S R , Hollowood D L , Honscheid K , James D J , March M , Menanteau F , Miquel R , Morgan R , Palmese A , Paz-Chinchón F , Pieres A , Plazas Malagón A A , Romer A K , Sanchez E , Scarpine V , Sevilla-Noarbe I , Soares-Santos M , Suchyta E , Tarle G , To C , Varga T N ,   DES Collaboration
Published: July 2022

ABSTRACT
Type Ia supernovae (SNe Ia) are used as standardizable candles to measure cosmological distances, but differences remain in their corrected luminosities which display a magnitude step as a function of host galaxy properties such as stellar mass and rest-frame U−R colour. Identifying the cause of these steps is key to cosmological analyses and provides insight into SN physics. Here we investigate the effects of SN progenitor ages on their light-curve properties using a galaxy-based forward model that we compare to the Dark Energy Survey 5-yr SN Ia sample. We trace SN Ia progenitors through time and draw their light-curve width parameters from a bimodal distribution according to their age. We find that an intrinsic luminosity difference between SNe of different ages cannot explain the observed trend between step size and SN colour. The data split by stellar mass are better reproduced by following recent work implementing a step in total-to-selective dust extinction ratio (RV) between low- and high-mass hosts, although an additional intrinsic luminosity step is still required to explain the data split by host galaxy U−R. Modelling the RV step as a function of galaxy age provides a better match overall. Additional age versus luminosity steps marginally improve the match to the data, although most of the step is absorbed by the width versus luminosity coefficient α. Furthermore, we find no evidence that α varies with SN age.
On the optical properties of resonant drag instabilities: variability of asymptotic giant branch and R Coronae Borealis stars
Authors: Steinwandel Ulrich P , Kaurov Alexander A , Hopkins Philip F , Squire Jonathan 
Published: July 2022

ABSTRACT
In dusty cool-star outflow or ejection events around asymptotic giant branch (AGB) or R Coronae Borealis or RCB-like stars, dust is accelerated by radiation from the star and coupled to the gas via collisional drag forces. It has recently been shown that such dust-gas mixtures are unstable to a super-class of instabilities called the resonant drag instabilities (RDIs), which promote dust clustering. We therefore consider idealized simulations of the RDIs operating on a spectrum of dust grain sizes subject to radiative acceleration (allowing for different grain optical properties), coupled to the gas with a realistic drag law, including or excluding the effects of magnetic fields and charged grains, and calculate for the first time how the RDIs could contribute to observed variability. We show that the RDIs naturally produce significant variations (spatially and temporally) ($\sim 10\!-\!20{{\ \rm per\ cent}}$ 1 σ-level) in the extinction, corresponding to $\sim 0.1\!-\!1\,$mag level in the stellar types above, on time-scales of order months to a year. The fluctuations are surprisingly robust to the assumed size of the source as they are dominated by large-scale modes, which also means their spatial structure could be resolved in some nearby systems. We also quantify how this produces variations in the line-of-sight grain size-distribution. All of these variations are similar to those observed, suggesting that the RDIs may play a key role driving observed spatial and temporal variability in dust extinction within dusty outflow/ejection events around cool stars. We further propose that the measured variations in grain sizes could directly be used to identify the presence of the RDIs in close by systems with observations.
Outflows and spectral evolution in the eclipsing AMXP SWIFT J1749.4–2807 with NICER, XMM-Newton, and NuSTAR
Authors: Marino A , Anitra A , Mazzola S M , Di Salvo T , Sanna A , Bult P , Guillot S , Mancuso G , Ng M , Riggio A , Albayati A C , Altamirano D , Arzoumanian Z , Burderi L , Cabras C , Chakrabarty D , Deiosso N , Gendreau K C , Iaria R , Manca A , Strohmayer T E 
Published: July 2022

ABSTRACT
The neutron star low-mass X-ray binary SWIFT J1749.4–2807 is the only known eclipsing accreting millisecond X-ray pulsar. In this manuscript, we perform a spectral characterization of the system throughout its 2021, 2-week-long outburst, analysing 11 NICER observations and quasi-simultaneous XMM-Newton and NuSTAR single observations at the outburst peak. The broad-band spectrum is well-modelled with a blackbody component with a temperature of ∼0.6 keV, most likely consistent with a hotspot on the neutron star surface, and a Comptonization spectrum with power-law index Γ ∼ 1.9, arising from a hot corona at ∼12 keV. No direct emission from the disc was found, possibly due to it being too cool. A high truncation radius for the disc, i.e. at ∼20–30 RG, was obtained from the analysis of the broadened profile of the Fe line in the reflection component. The significant detection of a blue-shifted Fe XXVI absorption line at ∼7 keV indicates weakly relativistic X-ray disc winds, which are typically absent in the hard state of X-ray binaries. By comparing the low flux observed during the outburst and the one expected in a conservative mass-transfer, we conclude that mass-transfer in the system is highly non-conservative, as also suggested by the wind detection. Finally, using the NICER spectra alone, we followed the system while it was fading to quiescence. During the outburst decay, as the spectral shape hardened, the hotspot on the neutron star surface cooled down and shrank, a trend which could be consistent with the pure power-law spectrum observed during quiescence.
Gravitational wave of intermediate-mass black holes in Population III star clusters
Authors: Wang Long , Tanikawa Ataru , Fujii Michiko 
Published: July 2022

ABSTRACT
Previous theoretical studies suggest that the Population III (Pop3) stars tend to form in extremely metal-poor gas clouds with approximately $10^5 \ \mathrm{M}_\odot$ embedded in mini dark matter haloes. Very massive stars can form via multiple collisions in Pop3 star clusters and eventually evolve to intermediate-mass black holes (IMBHs). In this work, we conduct star-by-star N-body simulations for modelling the long-term evolution of Pop3 star clusters. We find that if the mini dark matter haloes can survive today, these star clusters can avoid tidal disruption by the galactic environment and can efficiently produce IMBH–black hole (BH) mergers among a wide range of redshift from 0 to 20. The average gravitational wave event rate is estimated to be $0.1\!-\!0.8\ \mathrm{yr}^{-1} \,\mathrm{Gpc}^{-3}$, and approximately 40–80 per cent of the mergers occur at high redshift (z &gt; 6). The characteristic strain shows that a part of low-redshift mergers can be detected by LISA, TianQin, and Taiji, whereas most mergers can be covered by DECIGO and advanced LIGO/Virgo/KAGRA. Mergers with pair-instability BHs have a rate of approximately 0.01–0.15 yr−1 Gpc−3, which can explain the GW190521-like events.
GRANDMA observations of ZTF/Fink transients during summer 2021
Authors: Aivazyan V , Almualla M , Antier S , Baransky A , Barynova K , Basa S , Bayard F , Beradze S , Berezin D , Blazek M , Boutigny D , Boust D , Broens E , Burkhonov O , Cailleau A , Christensen N , Cejudo D , Coleiro A , Coughlin M W , Datashvili D , Dietrich T , Dolon F , Ducoin J-G , Duverne P-A , Marchal-Duval G , Galdies C , Granier L , Godunova V , Gokuldass P , Eggenstein H B , Freeberg M , Hello P , Inasaridze R , Ishida E E O , Jaquiery P , Kann D A , Kapanadze G , Karpov S , Kiendrebeogo R W , Klotz A , Kneip R , Kochiashvili N , Kou W , Kugel F , Lachaud C , Leonini S , Leroy A , Leroy N , Van Su A Le , Marchais D , Mašek M , Midavaine T , Möller A , Morris D , Natsvlishvili R , Navarete F , Noysena K , Nissanke S , Noonan K , Orange N B , Peloton J , Popowicz A , Pradier T , Prouza M , Raaijmakers G , Rajabov Y , Richmond M , Romanyuk Ya , Rousselot L , Sadibekova T , Serrau M , Sokoliuk O , Song X , Simon A , Stachie C , Taylor A , Tillayev Y , Turpin D , Vardosanidze M , Vlieghe J , Melo I Tosta e , Wang X F , Zhu J 
Published: July 2022

ABSTRACT
We present our follow-up observations with GRANDMA of transient sources revealed by the Zwicky Transient Facility (ZTF). Over a period of six months, all ZTF alerts were examined in real time by a dedicated science module implemented in the Fink broker, which will be used in filtering of transients discovered by the Vera C. Rubin Observatory. In this article, we present three selection methods to identify kilonova candidates. Out of more than 35 million alerts, a hundred sources have passed our selection criteria. Six were then followed-up by GRANDMA (by both professional and amateur astronomers). The majority were finally classified either as asteroids or as supernovae events. We mobilized 37 telescopes, bringing together a large sample of images, taken under various conditions and quality. To complement the orphan kilonova candidates, we included three additional supernovae alerts to conduct further observations during summer 2021. We demonstrate the importance of the amateur astronomer community that contributed images for scientific analyses of new sources discovered in a magnitude range r′ = 17 − 19 mag. We based our rapid kilonova classification on the decay rate of the optical source that should exceed 0.3 mag d−1. GRANDMA’s follow-up determined the fading rate within 1.5 ± 1.2 d post-discovery, without waiting for further observations from ZTF. No confirmed kilonovae were discovered during our observing campaign. This work will be continued in the coming months in the view of preparing for kilonova searches in the next gravitational-wave observing run O4.
Low spin-axis variations of circumbinary planets
Authors: Chen Renyi , Li Gongjie , Tao Molei 
Published: July 2022

ABSTRACT
Having a massive moon has been considered as a primary mechanism for stabilized planetary obliquity, an example of which being our Earth. This is, however, not always consistent with the exoplanetary cases. This article details the discovery of an alternative mechanism, namely that planets orbiting around binary stars tend to have low spin-axis variations. This is because the large quadrupole potential of the stellar binary could speed up the planetary orbital precession, and detune the system out of secular spin-orbit resonances. Consequently, habitable zone planets around the stellar binaries in low inclination orbits hold higher potential for regular seasonal changes comparing to their single star analogues.
A machine learning based approach to gravitational lens identification with the International LOFAR Telescope
Authors: Rezaei S , McKean J P , Biehl M , de Roo W , Lafontaine A 
Published: July 2022

ABSTRACT
We present a novel machine learning based approach for detecting galaxy-scale gravitational lenses from interferometric data, specifically those taken with the International LOFAR Telescope (ILT), which is observing the northern radio sky at a frequency of 150 MHz, an angular resolution of 350 mas and a sensitivity of 90 μJy beam−1 (1σ). We develop and test several Convolutional Neural Networks to determine the probability and uncertainty of a given sample being classified as a lensed or non-lensed event. By training and testing on a simulated interferometric imaging data set that includes realistic lensed and non-lensed radio sources, we find that it is possible to recover 95.3 per cent of the lensed samples (true positive rate), with a contamination of just 0.008 per cent from non-lensed samples (false positive rate). Taking the expected lensing probability into account results in a predicted sample purity for lensed events of 92.2 per cent. We find that the network structure is most robust when the maximum image separation between the lensed images is ≥3 times the synthesized beam size, and the lensed images have a total flux density that is equivalent to at least a 20σ (point-source) detection. For the ILT, this corresponds to a lens sample with Einstein radii ≥0.5 arcsec and a radio source population with 150 MHz flux densities ≥2 mJy. By applying these criteria and our lens detection algorithm we expect to discover the vast majority of galaxy-scale gravitational lens systems contained within the LOFAR Two Metre Sky Survey.
Spliceosomal SL1 RNA binding to U1-70K: the role of the extended RRM
Authors: Gopan Gopika , Ghaemi Zhaleh , Davis Caitlin M , Gruebele Martin 
Published: July 2022

Abstract
The RNA recognition motif (RRM) occurs widely in RNA-binding proteins, but does not always by itself support full binding. For example, it is known that binding of SL1 RNA to the protein U1-70K in the U1 spliceosomal particle is reduced when a region flanking the RRM is truncated. How the RRM flanking regions that together with the RRM make up an ‘extended RRM’ (eRRM) contribute to complex stability and structural organization is unknown. We study the U1-70K eRRM bound to SL1 RNA by thermal dissociation and laser temperature jump kinetics; long-time molecular dynamics simulations interpret the experiments with atomistic resolution. Truncation of the helix flanking the RRM on its N-terminal side, ‘N-helix,’ strongly reduces overall binding, which is further weakened under higher salt and temperature conditions. Truncating the disordered region flanking the RRM on the C-terminal side, ‘C-IDR’, affects the local binding site. Surprisingly, all-atom simulations show that protein truncation enhances base stacking interactions in the binding site and leaves the overall number of hydrogen bonds intact. Instead, the flanking regions of the eRRM act in a distributed fashion via collective interactions with the RNA when external stresses such as temperature or high salt mimicking osmotic imbalance are applied.
KMT2C-deficient tumors have elevated APOBEC mutagenesis and genomic instability in multiple cancers
Authors: Hu Xiaoju , Biswas Antara , De Subhajyoti 
Published: July 2022

Abstract
The histone methyltransferase KMT2C is among the most frequently mutated epigenetic modifier genes in cancer and plays an essential role in MRE11-dependent DNA replication fork restart. However, the effects of KMT2C deficiency on genomic instability during tumorigenesis are unclear. Analyzing 9,663 tumors from 30 cancer cohorts, we report that KMT2C mutant tumors have a significant excess of APOBEC mutational signatures in several cancer types. We show that KMT2C deficiency promotes APOBEC expression and deaminase activity, and compromises DNA replication speed and delays fork restart, facilitating APOBEC mutagenesis targeting single stranded DNA near stalled forks. APOBEC-mediated mutations primarily accumulate during early replication and tend to cluster along the genome and also in 3D nuclear domains. Excessive APOBEC mutational signatures in KMT2C mutant tumors correlate with elevated genome maintenance defects and signatures of homologous recombination deficiency. We propose that KMT2C deficiency is a likely promoter of APOBEC mutagenesis, which fosters further genomic instability during tumor progression in multiple cancer types.
Risk Factors for Acute Gastroenteritis Among Patients Hospitalized in 5 Veterans Affairs Medical Centers, 2016–2019
Authors: Balachandran Neha , Cates Jordan , Kambhampati Anita K , Marconi Vincent C , Whitmire Alexis , Morales Elena , Brown Sheldon T , Lama Diki , Rodriguez-Barradas Maria C , Moronez Rosalba Gomez , Domiguez Gilberto Rivera , Beenhouwer David O , Poteshkina Aleksandra , Matolek Zlatko Anthony , Holodniy Mark , Lucero-Obusan Cynthia , Agarwal Madhuri , Cardemil Cristina , Parashar Umesh , Mirza Sara A 
Published: July 2022

Abstract

Background
In the United States, ∼179 million acute gastroenteritis (AGE) episodes occur annually. We aimed to identify risk factors for all-cause AGE, norovirus-associated vs non-norovirus AGE, and severe vs mild/moderate AGE among hospitalized adults.

Methods
We enrolled 1029 AGE cases and 624 non-AGE controls from December 1, 2016, to November 30, 2019, at 5 Veterans Affairs Medical Centers. Patient interviews and medical chart abstractions were conducted, and participant stool samples were tested using the BioFire Gastrointestinal Panel. Severe AGE was defined as a modified Vesikari score of ≥11. Multivariate logistic regression was performed to assess associations between potential risk factors and outcomes; univariate analysis was conducted for norovirus-associated AGE due to limited sample size.

Results
Among 1029 AGE cases, 551 (54%) had severe AGE and 44 (4%) were norovirus positive. Risk factors for all-cause AGE included immunosuppressive therapy (adjusted odds ratio [aOR], 5.6; 95% CI, 2.7–11.7), HIV infection (aOR, 3.9; 95% CI, 1.8–8.5), severe renal disease (aOR, 3.1; 95% CI, 1.8–5.2), and household contact with a person with AGE (aOR, 2.9; 95% CI, 1.3–6.7). Household (OR, 4.4; 95% CI, 1.6–12.0) and non-household contact (OR, 5.0; 95% CI, 2.2–11.5) with AGE was associated with norovirus-associated AGE. Norovirus positivity (aOR, 3.4; 95% CI, 1.3–8.8) was significantly associated with severe AGE.

Conclusions
Patients with immunosuppressive therapy, HIV, and severe renal disease should be monitored for AGE and may benefit from targeted public health messaging regarding AGE prevention. These results may also direct future public health interventions, such as norovirus vaccines, to specific high-risk populations.
Involvement of NGATHA-Like 1 Transcription Factor in Boron Transport under Low and High Boron Conditions
Authors: Tsednee Munkhtsetseg , Tanaka Mayuki , Giehl Ricardo Fh , von Wirén Nicolaus , Fujiwara Toru 
Published: July 2022

Abstract
NGATHA-Like 1 (NGAL1) transcription factor has been identified as a gene regulated through AUG-stop-mediated boron (B)-dependent translation stall; however, its function in B response remains unknown. Here, we show that NGAL1 plays an important role in the maintenance of B transport under both low- and high-B conditions in Arabidopsis thaliana. NGAL1 mRNA is accumulated predominantly in shoots in response to B stress. Independent ngal1 mutants carrying transferred DNA (T-DNA) and Ds-transposon insertions exhibit reduced B concentrations in aerial tissues and produce shortened and reduced number of siliques when B supply is limited. Furthermore, the expression of B transporter genes including nodulin 26-like intrinsic protein 6; 1 (NIP6;1), NIP5;1, NIP7;1 and borate exporter 1 (BOR1) is significantly decreased in ngal1 mutants under low-B condition, suggesting that NGAL1 is required for the transcript accumulation of B transporter genes to facilitate B transport and distribution under B limitation. Under high-B condition, ngal1 mutants exhibit reduced growth and increased B concentration in their shoots. The accumulation of BOR4 mRNA, a B transporter required for B efflux to soil, is significantly reduced in roots of ngal1 plants under high-B condition, suggesting that NGAL1 is involved in the upregulation of BOR4 in response to excess B. Together, our results indicate that NGAL1 is involved in the transcriptional regulation of B transporter genes to facilitate B transport and distribution under both low- and high-B conditions.
Arabidopsis Glucan Synthase-Like1 (GSL1) Is Required for Tolerance to Low-Calcium Conditions and Exhibits a Function Comparable to GSL10
Authors: Shikanai Yusuke , Takahashi Satomi , Enomoto Yusuke , Yamagami Mutsumi , Yamaguchi Katsushi , Shigenobu Shuji , Kamiya Takehiro , Fujiwara Toru 
Published: July 2022

Abstract
Crops that exhibit symptoms of calcium (Ca) deficiency constitute a major agricultural problem. Molecular breeding of resistant cultivars is a promising method for overcoming this problem. However, the involved genes must first be identified. Here, we show that the glucan synthase-like (GSL) 1 gene is essential for low-Ca tolerance in Arabidopsis thaliana. GSL1 is homologous to GSL10, which we previously showed was essential for low-Ca tolerance. Under low-Ca conditions, gsl1 mutants exhibit reduced growth and the onset of necrosis in new leaves. These symptoms are typical of Ca-deficient crops. A grafting experiment suggested that the shoot genotype, but not the root genotype, was important for the suppression of shoot necrosis. The ectopic accumulation of callose under low-Ca conditions was significantly reduced in gsl1 mutants compared with wild-type plants. Because the corresponding single-mutant phenotypes are similar, we investigated the interaction between GSL1 and GSL10 by testing the gsl1 gsl10 double mutant for sensitivity to low-Ca conditions. The double mutant exhibited a more severe phenotype than did the single mutants, indicating that the effects of GSL1 and GSL10 on low-Ca tolerance are additive. Because GSL genes are highly conserved within the plant kingdom, the GSL loci may be useful for breeding low-Ca tolerant crops.