bluuebunny/crossref_metadata_2025_split huggingface dataset:
A white dwarf bound to the transiting planetary system WASP-98
Authors: Southworth John , Tremblay Pier-Emmanuel , Gänsicke Boris T , Evans Daniel , Močnik Teo 
Published: August 2020

ABSTRACT
WASP-98 is a planetary system containing a hot Jupiter transiting a late-G dwarf. A fainter star, 12 arcsec away, has previously been identified as a white dwarf, with a distance and proper motion consistent with a physical association with the planetary system. We present spectroscopy of the white dwarf, with the aim of determining its mass, radius, and temperature and hence the age of the system. However, the spectra show the featureless continuum and lack of spectral lines characteristic of the DC class of white dwarfs. We therefore fitted theoretical white dwarf spectra to the ugriz apparent magnitudes and Gaia DR2 parallax of this object in order to determine its physical properties and the age of the system. We find that the system is old, with a lower limit of 3.6 Gyr, but theoretical uncertainties preclude a precise determination of its age. Its kinematics are consistent with membership of the thick disc, but do not allow us to rule out the thin-disc alternative. The old age and low metallicity of the system suggest that it is subject to an age–metallicity relation, but analysis of the most metal-rich and metal-poor transiting planetary systems yields only insubstantial evidence of this. We conclude that the study of bound white dwarfs can yield independent ages to planetary systems, but such analysis may be better suited to DA and DB rather than DC white dwarfs.
The astrophysical odds of GW151216
Authors: Ashton Gregory , Thrane Eric 
Published: August 2020

ABSTRACT
The gravitational-wave candidate GW151216 is a proposed binary black hole event from the first observing run of the Advanced LIGO detectors. Not identified as a bona fide signal by the LIGO–Virgo collaboration, there is disagreement as to its authenticity, which is quantified by pastro, the probability that the event is astrophysical in origin. Previous estimates of pastro from different groups range from 0.18 to 0.71, making it unclear whether this event should be included in population analyses, which typically require pastro &gt; 0.5. Whether GW151216 is an astrophysical signal or not has implications for the population properties of stellar-mass black holes and hence the evolution of massive stars. Using the astrophysical odds, a Bayesian method that uses the signal coherence between detectors and a parametrized model of non-astrophysical detector noise, we find that pastro = 0.03, suggesting that GW151216 is unlikely to be a genuine signal. We also analyse GW150914 (the first gravitational-wave detection) and GW151012 (initially considered to be an ambiguous detection) and find pastro values of 1 and 0.997, respectively. We argue that the astrophysical odds presented here improve upon traditional methods for distinguishing signals from noise.
First 3D morpho-kinematic model of supernova remnants. The case of VRO 42.05.01 (G166.0+4.3)
Authors: Derlopa S , Boumis P , Chiotellis A , Steffen W , Akras S 
Published: August 2020

ABSTRACTWe present the first three-dimensional (3D) morpho-kinematic (MK) model of a supernova remnant (SNR), using as a case study the Galactic SNR VRO 42.05.01. We employed the astrophysical code SHAPE in which wide field imaging and high-resolution spectroscopic data were utilized, to reconstruct its 3D morphology and kinematics. We found that the remnant consists of three basic distinctive components that we call: a ‘shell’, a ‘wing’, and a ‘hat’. With respect to their kinematical behaviour, we found that the ‘wing’ and the ‘shell’ have similar expansion velocities (Vexp = 115 ± 5 km s−1). The ‘hat’ presents the lowest expansion velocity of the remnant (Vexp = 90 ± 20 km s−1), while the upper part of the ‘shell’ presents the highest velocity with respect to the rest of the remnant (Vexp = 155 ± 15 km s−1). Furthermore, the whole nebula has an inclination of ∼3°–5° with respect to the plane of the sky and a systemic velocity of Vsys = −17 ± 3 km s−1. We discuss the interpretation of our model results regarding the origin and evolution of the SNR and we suggest that VRO 42.05.01 had an interaction history with an inhomogeneous ambient medium most likely shaped by the mass outflows of its progenitor star.
SDSS-IV MaNGA: Bayesian analysis of the star formation history of low-mass galaxies in the local Universe
Authors: Zhou Shuang , Mo H J , Li Cheng , Boquien Médéric , Rossi Graziano 
Published: August 2020

ABSTRACT
We measure the star formation histories (SFHs) of a sample of low-mass galaxies with M* &lt; 109 M⊙ from the SDSS-IV MaNGA survey. The large number of IFU spectra for each galaxy are either combined to reach a high signal to noise ratio or used to investigate spatial variations. We use Bayesian inferences based on full spectrum fitting. Our analysis based on Bayesian evidence ratio indicates a strong preference for a model that allows the presence of an old stellar population, and that an improper model for the SFH can significantly underestimate the old population in these galaxies. The addition of near-infrared photometry to the constraining data can further distinguish between different SFH model families and significantly tighten the constraints on the mass fraction in the old population. On average more than half of the stellar mass in present-day low-mass galaxies formed at least 8 Gyr ago, while about 30 per cent within the past 4 Gyr. Satellite galaxies on average have formed their stellar mass earlier than central galaxies. The radial dependence of the SFH is quite weak. Our results suggest that most of the low-mass galaxies have an early episode of active star formation that produces a large fraction of their present stellar mass.
Energy-dependent nebula extent and spatially resolved spectra of the pulsar wind nebula 3C 58
Authors: Lu Fang-Wu , Gao Quan-Gui , Zhang Li 
Published: August 2020

ABSTRACT
3C 58 is a pulsar wind nebula (PWN) that shows an interesting energy-dependent nebula extent and spatial variations of the photon index and surface brightness in the X-ray band. These observations provide useful information with which to study the spatially dependent radiative cooling of electrons and the energy-dependent transport mechanisms within the nebula. In this paper, the energy-dependent nebula extent and spatially resolved spectra of this PWN are investigated in the framework of a spatially dependent particle transport model. The observations of the nebula, including the photon spectral energy distribution, spatial variations of the X-ray spectrum, and measurements of the nebula extent, can be naturally explained in this model. Our results show that the energy-dependent nebula extent favours an advection–diffusion scenario with advection-dominated transport, and the variations of the nebula extent with energy in the X-ray band can be attributed to the cooling losses of high-energy electrons affected by synchrotron burn-off. Particle diffusion plays an important role in modifying the spatial variations of the photon index and surface brightness in the X-ray band. The radial extents of the nebula at radio, GeV and TeV energies are predicted by the model, indicating that the nebula extent of 3C 58 varies with energy in these bands. The analyses show that the dependence of the adiabatic cooling rate and synchrotron radiation on the spectral index of injected particles is important for changing the nebula extent at different energies.
Does the structure of Population III supernova ejecta affect the elemental abundance of extremely metal-poor stars?
Authors: Chiaki Gen , Tominaga Nozomu 
Published: August 2020

ABSTRACT
The first generation of metal-free (Population III) stars are crucial for the production of heavy elements in the earliest phase of structure formation. Their mass scale can be derived from the elemental abundance pattern of extremely metal-poor (EMP) stars, which are assumed to inherit the abundances of uniformly mixed supernova (SN) ejecta. If the expanding ejecta maintains its initial stratified structure, the elemental abundance pattern of EMP stars might be different from that from uniform ejecta. In this work, we perform numerical simulations of the metal enrichment from stratified ejecta for normal core-collapse SNe (CCSNe) with a progenitor mass $25 \ {\rm M_{\bigodot }}$ and explosion energies 0.7–10 B ($1 \ {\rm B} = 10^{51} \ \rm erg$). We find that SN shells fall back into the central minihalo in all models. In the recollapsing clouds, the abundance ratio [M/Fe] for stratified ejecta is different from the one for uniform ejecta only within ±0.4 dex for any element M. We also find that, for the largest explosion energy (10 B), a neighbouring halo is also enriched. Only the outer layers containing Ca or lighter elements reach the halo, where [C/Fe] = 1.49. This means that C-enhanced metal-poor stars can form from the CCSN even with an average abundance ratio [C/Fe] = −0.65.
A wide-area GMRT 610-MHz survey of ELAIS N1 field
Authors: Ishwara-Chandra C H , Taylor A R , Green D A , Stil J M , Vaccari M , Ocran E F 
Published: August 2020

ABSTRACT
In this paper, we present a wide-area 610-MHz survey of the ELAIS N1 field with the GMRT, covering an area of 12.8 deg2 at a resolution of 6 arcsec and with an rms noise of ∼40 $\mu$Jy beam−1. This is equivalent to ∼20 $\mu$Jy beam−1 rms noise at 1.4 GHz for a spectral index of −0.75. The primary goal of the survey was to study the polarized sky at sub-mJy flux densities at &lt; GHz frequencies, alongwith a range of other science goals such as investigations into the nature of the low-frequency $\mu$Jy source populations and alignments of radio jets. A total of 6400 sources were found in this region, the vast majority of them compact. The sample jointly detected by GMRT at 610 MHz and by VLA FIRST at 1.4 GHz has a median spectral index of −0.85 ± 0.05 and a median 610-MHz flux density of 4.5 mJy. This region has a wealth of ancillary data, which is useful to characterize the detected sources. The multiwavelength crossmatching resulted optical/IR counterparts to ∼90 per cent of the radio sources, with a significant fraction having at least photometric redshift. Due to the improved sensitivity of this survey over preceding ones, we have discovered six giant radio sources (GRSs), with three of them at z ∼ 1 or higher. This implies that the population of GRS may be more abundant and common than known to date and if true, this has implications for the luminosity function and the evolution of radio sources. We have also identified several candidate-extended relic sources.
The next-generation X-ray galaxy survey with eROSITA
Authors: Basu-Zych Antara R , Hornschemeier Ann E , Haberl Frank , Vulic Neven , Wilms Jörn , Zezas Andreas , Kovlakas Konstantinos , Ptak Andrew , Dauser Thomas 
Published: August 2020

ABSTRACT
eROSITA, launched on 2019 July 13, will be completing the first all-sky survey in the soft and medium X-ray band in nearly three decades. This 4-yr survey, finishing in late 2023, will present a rich legacy for the entire astrophysics community and complement upcoming multiwavelength surveys (with, e.g. the Large Synoptic Survey Telescope and the Dark Energy Survey). Besides the major scientific aim to study active galactic nuclei (AGNs) and galaxy clusters, eROSITAwill contribute significantly to X-ray studies of normal (i.e. not AGN) galaxies. Starting from multiwavelength catalogues, we measure star formation rates and stellar masses for 60 212 galaxies constrained to distances of 50–200 Mpc. We chose this distance range to focus on the relatively unexplored volume outside the local Universe, where galaxies will be largely spatially unresolved and probe a range of X-ray luminosities that overlap with the low luminosity and/or highly obscured AGN population. We use the most recent X-ray scaling relations as well as the on-orbit eROSITA instrument performance to predict the X-ray emission from XRBs and diffuse hot gas and to perform both an analytic prediction and an end-to-end simulation using the mission simulation software, sixte. We consider potential contributions from hidden AGN and comment on the impact of normal galaxies on the measurement of the faint end of the AGN luminosity function. We predict that the eROSITA 4-yr survey, will detect ≳15 000 galaxies (3σ significance) at 50–200 Mpc, which is ∼100 × more normal galaxies than detected in any X-ray survey to date.
Early light curves of Type II supernovae interacting with a circumstellar disc
Authors: Nagao T , Maeda K , Ouchi R 
Published: August 2020

ABSTRACT
Type II supernovae (SNe) interacting with disc-like circumstellar matter (CSM) have been suggested as an explanation of some unusual Type II SNe, e.g. the so-called impossible SN, iPTF14hls. There are some radiation hydrodynamic simulations for such SNe interacting with a CSM disc. However, such disc interaction models so far have not included the effect of the ionization and recombination processes in the SN ejecta, i.e. the fact that the photosphere of Type IIP SNe between ∼10 and ∼100 d is regulated by the hydrogen recombination front. We calculate light curves for Type IIP SNe interacting with a CSM disc viewed from the polar direction, and examine the effects of the disc density and opening angle on their bolometric light curves. This work embeds the shock interaction model of Moriya et al. within the Type IIP SN model of Kasen & Woosley, for taking into account the effects of the ionization and recombination in the SN ejecta. We demonstrate that such interacting SNe show three phases with different photometric and spectroscopic properties, following the change in the energy source: First few tens of days after explosion (phase 1), ∼10 to ∼100 d (phase 2), and days after that (phase 3). From the calculations, we conclude that such hidden CSM disc cannot account for overluminous Type IIP SNe. We find that the luminosity ratio between phase 1 and phase 2 has information on the opening angle of the CSM disc. We thus encourage early photometric and spectroscopic observations of interacting SNe for investigating their CSM geometry.
Type III-A CRISPR-associated protein Csm6 degrades cyclic hexa-adenylate activator using both CARF and HEPN domains
Authors: Smalakyte Dalia , Kazlauskiene Migle , F. Havelund Jesper , Rukšėnaitė Audronė , Rimaite Auguste , Tamulaitiene Giedre , Færgeman Nils J , Tamulaitis Gintautas , Siksnys Virginijus 
Published: August 2020

Abstract
The type III CRISPR–Cas systems provide immunity against invading nucleic acids through the coordinated transcription-dependent DNA targeting and cyclic adenylate (cAn)-activated RNA degradation. Here, we show that both these pathways contribute to the Streptococcus thermophilus (St) type III-A CRISPR–Cas immunity. HPLC-MS analysis revealed that in the heterologous Escherichia coli host the StCsm effector complex predominantly produces cA5 and cA6. cA6 acts as a signaling molecule that binds to the CARF domain of StCsm6 to activate non-specific RNA degradation by the HEPN domain. By dissecting StCsm6 domains we demonstrate that both CARF and HEPN domains act as ring nucleases that degrade cAns to switch signaling off. CARF ring nuclease converts cA6 to linear A6&gt;p and to the final A3&gt;p product. HEPN domain, which typically degrades RNA, also shows ring nuclease activity and indiscriminately degrades cA6 or other cAns down to A&gt;p. We propose that concerted action of both ring nucleases enables self-regulation of the RNase activity in the HEPN domain and eliminates all cAn secondary messengers in the cell when viral infection is combated by a coordinated action of Csm effector and the cA6-activated Csm6 ribonuclease.
The crystal structure of human XPG, the xeroderma pigmentosum group G endonuclease, provides insight into nucleotide excision DNA repair
Authors: González-Corrochano Rocío , Ruiz Federico M , Taylor Nicholas M I , Huecas Sonia , Drakulic Srdja , Spínola-Amilibia Mercedes , Fernández-Tornero Carlos 
Published: August 2020

Abstract
Nucleotide excision repair (NER) is an essential pathway to remove bulky lesions affecting one strand of DNA. Defects in components of this repair system are at the ground of genetic diseases such as xeroderma pigmentosum (XP) and Cockayne syndrome (CS). The XP complementation group G (XPG) endonuclease cleaves the damaged DNA strand on the 3′ side of the lesion coordinated with DNA re-synthesis. Here, we determined crystal structures of the XPG nuclease domain in the absence and presence of DNA. The overall fold exhibits similarities to other flap endonucleases but XPG harbors a dynamic helical arch that is uniquely oriented and defines a gateway. DNA binding through a helix-2-turn-helix motif, assisted by one flanking α-helix on each side, shows high plasticity, which is likely relevant for DNA scanning. A positively-charged canyon defined by the hydrophobic wedge and β-pin motifs provides an additional DNA-binding surface. Mutational analysis identifies helical arch residues that play critical roles in XPG function. A model for XPG participation in NER is proposed. Our structures and biochemical data represent a valuable tool to understand the atomic ground of XP and CS, and constitute a starting point for potential therapeutic applications.
Healthy lifestyle reduces incidence of trace/positive proteinuria and rapid kidney function decline after 2 years: from the Japan Ningen Dock study
Authors: Okada Rieko , Tsushita Kazuyo , Wakai Kenji , Kato Kiminori , Wada Takashi , Shinohara Yukito 
Published: August 2020

Abstract

Background
Lifestyle modification is recommended for subjects with trace proteinuria during health checkups. However, whether overall healthy lifestyle reduces the incidence of trace/positive proteinuria or rapid decline in estimated glomerular filtration rate (eGFR) is not clarified.

Methods
A total of 451 534 people (277 494 men and 174 040 women) ages 20–79 years with negative proteinuria were included. The number of three healthy lifestyle factors (LFs) was assessed: noncurrent smoking, healthy eating habits (late dinner, snacking and skipping breakfast &lt;3 times/week) and body mass index &lt;25. The incidence of trace (±) and positive (≥1+) proteinuria by the dipstick method and eGFR decline ≥20% over 2 years were compared with the number of healthy LFs.

Results
The incidence of trace/positive proteinuria and rapid eGFR decline decreased with an increasing number of healthy LFs as follows: odds ratios (ORs) for trace proteinuria, 0.91 [95% confidence interval (CI) 0.86–0.96], 0.82 (0.78–0.87) and 0.72 (0.68–0.77); ORs for positive proteinuria, 0.76 (95% CI 0.67–0.86), 0.56 (0.50–0.63) and 0.46 (0.40–0.53); and ORs for an eGFR decline ≥20%, 0.93 (95% CI 0.82–1.05), 0.90 (0.79–1.02) and 0.81 (0.70–0.93) for those with one, two and three healthy LFs compared with those with none of the three healthy LFs, respectively. Overall, subjects with a healthy lifestyle showed 28, 54 and 19% reduced risk of developing trace proteinuria, positive proteinuria and eGFR decline ≥20%, respectively, compared with those with an unhealthy lifestyle after 2 years. This association was similarly observed even among subjects without hypertension (HT) or diabetes mellitus (DM).

Conclusions
Subjects with an overall healthy lifestyle showed a lower incidence of trace/positive proteinuria by dipstick test and rapid eGFR decline over 2 years in a nationwide general population. Thus lifestyle modification should be recommended for subjects with trace proteinuria during health checkups, even for subjects without HT or DM.
Buyer–Supplier Relationships and Embeddedness
Authors: Kim Yusoon , Choi Thomas Y. 
Published: August 2020

Abstract
This chapter begins with the observation that a supplier is embedded not only within the dyad (i.e., the buyer) but also within its own extended ties (i.e., its suppliers). Looking at the buyer–supplier relationships via the lens of embeddedness allows us to consider the duality of relational outcomes—the primary outcome contained in the dyad and the incidental outcome on the supplier’s part. The chapter conceptualizes dyadic embeddedness in the buyer–supplier context and demonstrates how that dyadic embeddedness is accountable for the diverse relational outcomes and helps resolve some puzzling observations that have been made in the literature. How a supplier relates to its buyer in the dyad constrains how it perceives and behaves outside the dyad, which in turn would have spillover effect on the buyer–supplier dyad. As such, taking the embeddedness view broadens our understanding of the dynamics of buyer–supplier relationships.
Organizational and Temporal Shifts in Procurement Analytics
Authors: Handfield Robert B. , Jeong Seongkyoon 
Published: August 2020

Abstract
Academic research in the early twenty-first century highlights the emerging role of analytics in all functions, including procurement and supply chain. Given the rapid shifts in technology that are under way in this field, academic research may struggle to keep up with the dynamic evolution of procurement platforms. This chapter assesses the current set of procurement analytics–based research and observes the organizational and temporal evolution of how procurement analytics is proceeding. Next, the chapter reviews a number of procurement platforms and interviews with procurement executives to suggest that academic research is at the same nascent stage as the evolution of the technology, which is often highly touted but is in the early stages of development. The analysis also highlights the importance of data integrity and quality as major roadblocks preventing the adoption of advanced procurement analytics. However, the analysis suggests that technologies will continue to propel the expansion of organizational and temporal shifts in procurement analytics, enabled by the emerging digital environment and evolving technologies such as data analytics and cognitive analytics. As a result, we will likely continue to witness massive changes in the procurement analytics environment in the next three to five years. The chapter concludes that although the current maturity of procurement analytics is low, supply management should adopt a leadership role in advancing the procurement analytics scope and scale.
Emerging Technologies in Supply Management
Authors: Prud’homme Andrea M. , Gray John V. , Barley Andrew C. 
Published: August 2020

Abstract
This chapter looks at emerging technologies and their use in supply management processes as a means to improve effectiveness through improved speed and accuracy, at a reduced cost. Many technologies are finding their way into supply management, with differing levels of penetration and application and with mixed results. It may be challenging for supply management professionals to understand how, when, and where these technologies are likely to yield positive results. This chapter reviews several technologies, including artificial intelligence/machine learning, big data/advanced analytics, blockchain, cloud computing, conversational things (e.g., chatbots), immersive technologies (e.g., virtual and augmented reality), and robotic process automation. Findings indicate that the primary advantages are achieved by improving current processes and workflows, rather than that these technologies are currently disrupting or will fundamentally change supply management. Another important finding is the importance of “clean data” inputs, something that artificial intelligence can help with and that is foundational for successful robotic process automation.