bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mixed Modes and Asteroseismic Surface Effects. II. Subgiant Systematics
Authors: Ong 王 J. M. Joel 加冕 , Basu Sarbani , Lund Mikkel N. , Bieryla Allyson , Viani Lucas S. , Latham David W. 
Published: November 2021

Abstract
Models of solar-like oscillators yield acoustic modes at different frequencies than would be seen in actual stars possessing identical interior structure, due to modeling error near the surface. This asteroseismic “surface term” must be corrected when mode frequencies are used to infer stellar structure. Subgiants exhibit oscillations of mixed acoustic (p-mode) and gravity (g-mode) character, which defy description by the traditional p-mode asymptotic relation. Since nonparametric diagnostics of the surface term rely on this description, they cannot be applied to subgiants directly. In Paper I, we generalized such nonparametric methods to mixed modes, and showed that traditional surface-term corrections only account for mixed-mode coupling to, at best, first order in a perturbative expansion. Here, we apply those results, modeling subgiants using asteroseismic data. We demonstrate that, for grid-based inference of subgiant properties using individual mode frequencies, neglecting higher-order effects of mode coupling in the surface term results in significant systematic differences in the inferred stellar masses, and measurable systematics in other fundamental properties. While these systematics are smaller than those resulting from other choices of model construction, they persist for both parametric and nonparametric formulations of the surface term. This suggests that mode coupling should be fully accounted for when correcting for the surface term in seismic modeling with mixed modes, irrespective of the choice of correction used. The inferred properties of subgiants, in particular masses and ages, also depend on the choice of surface-term correction, in a different manner from those of both main-sequence and red giant stars.
Halo-model Analysis of the Clustering of Photometric Luminous Red Galaxies at 0.10 ≤ z ≤1.05 from the Subaru Hyper Suprime-Cam Survey
Authors: Ishikawa Shogo , Okumura Teppei , Oguri Masamune , Lin Sheng-Chieh 
Published: November 2021

Abstract
We present the clustering analysis of photometric luminous red galaxies (LRGs) at a redshift range of 0.1 ≤ z ≤ 1.05 using 615,317 photometric LRGs selected from the Hyper Suprime-Cam Subaru Strategic Program, covering ∼124 deg2. Our sample covers a broad range of stellar masses and photometric redshifts and enables a halo occupation distribution analysis to study the redshift and stellar-mass dependence of dark halo properties of LRGs. We find a tight correlation between the characteristic dark halo mass to host central LRGs,

M

min

, and the number density of LRGs, independently of redshifts, indicating that the formation of LRGs is associated with the global environment. The

M

min

of LRGs depends only weakly on the stellar mass M
⋆ at M
⋆ ≲ 1010.75
h
−2
M
⊙ at 0.3 < z < 1.05, in contrast to the case for all photometrically selected galaxies, for which

M

min

shows significant dependence on M
⋆ even at low M
⋆. The weak stellar-mass dependence is indicative of the dark halo mass being the key parameter for the formation of LRGs, rather than the stellar mass. Our result suggests that the halo mass of ∼1012.5±0.2
h
−1
M
⊙ is the critical mass for an efficient halo quenching due to the halo environment. We compare our result with the result of the hydrodynamical simulation to find that low-mass LRGs at z ∼ 1 will increase their stellar masses by an order of magnitude from z = 1 to 0 through mergers and satellite accretions, and that a large fraction of massive LRGs at z < 0.9 consist of LRGs that recently migrated from massive green valley galaxies or those that evolved from less massive LRGs through mergers and satellite accretions.
A VLA Survey of Late-time Radio Emission from Superluminous Supernovae and the Host Galaxies
Authors: Hatsukade Bunyo , Tominaga Nozomu , Morokuma Tomoki , Morokuma-Matsui Kana , Matsuda Yuichi , Tamura Yoichi , Niinuma Kotaro , Motogi Kazuhiro 
Published: November 2021

Abstract
We present the results of 3 GHz radio continuum observations of 23 superluminous supernovae (SLSNe) and their host galaxies by using the Karl G. Jansky Very Large Array conducted 5–21 yr after the explosions. The sample consists of 15 Type I and 8 Type II SLSNe at z < 0.3, providing one of the largest samples of SLSNe with late-time radio data. We detected radio emission from one SLSN (PTF10hgi) and five hosts with a significance of >5σ. No time variability is found in late-time radio light curves of the radio-detected sources in a timescale of years except for PTF10hgi, whose variability is reported in a separate study. Comparison of star formation rates (SFRs) derived from the 3 GHz flux densities with those derived from SED modeling based on UV–NIR data shows that four hosts have an excess of radio SFRs, suggesting obscured star formation. Upper limits for undetected hosts and stacked results show that the majority of the SLSN hosts do not have a significant obscured star formation. By using the 3 GHz upper limits, we constrain the parameters for afterglows arising from interaction between initially off-axis jets and circumstellar medium (CSM). We found that the models with higher energies (E
iso ≳ several × 1053 erg) and CSM densities (n ≳ 0.01 cm−3) are excluded, but lower energies or CSM densities are not excluded with the current data. We also constrained the models of pulsar wind nebulae powered by a newly born magnetar for a subsample of SLSNe with model predictions in the literature.
Optical and Near-infrared Pulsation Properties of RR Lyrae and Population II Cepheid Variables in the Messier 15 Globular Cluster
Authors: Bhardwaj Anupam , Rejkuba Marina , Sloan G. C. , Marconi Marcella , Yang Soung-Chul 
Published: November 2021

Abstract
Messier 15 (NGC 7078) is an old and metal-poor post core-collapse globular cluster that hosts a rich population of variable stars. We report new optical (gi) and near-infrared (NIR, JK

s
) multi-epoch observations for 129 RR Lyrae, 4 Population II Cepheids (3 BL Herculis, 1 W Virginis), and 1 anomalous Cepheid variable candidate in M15 obtained using the MegaCam and the WIRCam instruments on the 3.6 m Canada–France–Hawaii Telescope. Multi-band data are used to improve the periods and classification of variable stars, and determine accurate mean magnitudes and pulsational amplitudes from the light curves fitted with optical and NIR templates. We derive optical and NIR period–luminosity relations for RR Lyrae stars which are best constrained in the K

s
band,

m

K

s

=
−
2.333

(
0.054
)
log
P
+
13.948

(
0.015
)

with a scatter of only 0.037 mag. Theoretical and empirical calibrations of RR Lyrae period–luminosity–metallicity relations are used to derive a true distance modulus to M15: 15.196 ± 0.026 (statistical) ± 0.039 (systematic) mag. Our precise distance moduli based on RR Lyrae stars and Population II Cepheid variables are mutually consistent and agree with recent distance measurements in the literature based on Gaia parallaxes and other independent methods.
Probing the Time Variation of a Fine Structure Constant Using Galaxy Clusters and the Quintessence Model
Authors: Liu 刘 Zhi-E 志娥 , Liu 刘 Wen-Fei 文斐 , Zhang 张 Tong-Jie 同杰 , Zhai 翟 Zhong-Xu 忠旭 , Bora Kamal 
Published: November 2021

Abstract
We explore a possible time variation of the fine structure constant (α ≡ e
2/ℏ
c) using the Sunyaev–Zel’dovich effect measurements of galaxy clusters along with their X-ray observations. Specifically, the ratio of the integrated Comptonization parameter

Y

SZ

D

A

2

and its X-ray counterpart Y

X
is used as an observable to constrain the bounds on the variation of α. Considering the violation of the cosmic distance duality relation, this ratio depends on the fine structure constant of ∼ α
3. We use the quintessence model to provide the origin of α time variation. In order to give a robust test on α variation, two galaxy cluster samples, the 61 clusters provided by the Planck collaboration and the 58 clusters detected by the South Pole Telescope (SPT), are collected for analysis. Their X-ray observations are given by the XMM-Newton survey. Our results give

ζ
=
−

0.203

−
0.099

+
0.101

for the Planck sample and

ζ
=
−

0.043

−
0.148

+
0.165

for the SPT sample, indicating that α is constant with redshift within 3σ and 1σ for the two samples, respectively.
A MeerKAT 1.28 GHz Atlas of Southern Sources in the IRAS Revised Bright Galaxy Sample
Authors: Condon J. J. , Cotton W. D. , Jarrett T. , Marchetti L. , Matthews A. M. , Mauch T. , Moloko M. E. 
Published: November 2021

Abstract
The IRAS Revised Bright Galaxy Sample (RBGS) comprises galaxies and unresolved mergers stronger than S = 5.24 Jy at λ = 60 μm with Galactic latitudes ∣b∣ > 5°. Nearly all are dusty star-forming galaxies whose radio continuum and far-infrared luminosities are proportional to their current rates of star formation. We used the MeerKAT array of 64 dishes to make 5 × 3 minutes snapshot observations at ν = 1.28 GHz covering all 298 southern (J2000 δ < 0°) RBGS sources identified with external galaxies. The resulting images have θ ≈ 7.″5 FWHM resolution and rms fluctuations σ ≈ 20 μJy beam−1 ≈ 0.26 K low enough to reveal even faint disk emission. The rms position uncertainties are σ

α
≈ σ

δ
≈ 1″ relative to accurate near-infrared positions, and the image dynamic ranges are DR ≳ 104: 1. Cropped MeerKAT images of all 298 southern RBGS sources are available in FITS format from 10.48479/dnt7-6q05.
Magnetohydrodynamic Modeling of the Solar Corona with an Effective Implicit Strategy
Authors: Feng Xueshang , Wang Haopeng , Xiang Changqing , Liu Xiaojing , Zhang Man , Zhao Jingmin , Shen Fang 
Published: November 2021

Abstract
In this paper, we design an effective and robust model to solve the 3D single-fluid solar wind plasma magnetohydrodynamics (MHD) problem of low plasma β. This MHD model is formulated on a six-component composite grid system free of polar singularities. The computational domain ranges from the solar surface to the super-Alfvénic region. As common to all MHD codes, this code must handle the physical positivity-preserving property, time-step enlargement, and magnetic field divergence-free maintenance. To maintain physical positivity, we employ a positivity-preserving Harten–Lax–van Leer Riemann solver and take a self-adjusting and positivity-preserving method for variable reconstruction. To loosen the time-step limitation, we resort to the implicit lower–upper symmetric Gauss–Seidel method and keep the sparse Jacobian matrix diagonally dominant to improve the convergence rate. To deal with the constant theme of a magnetic field that is divergence-free, we adopt a globally solenoidality-preserving approach. After establishing the solar wind model, we use its explicit and implicit versions to numerically investigate the steady-state solar wind in Carrington rotations (CRs) 2172 and 2210. Both simulations achieve almost the same results for the two CRs and are basically consistent with solar coronal observations and mapped in situ interplanetary measurements. Furthermore, we use the implicit method to conduct an ad hoc simulation by multiplying the initial magnetic field of CR 2172 with a factor of 6. The simulation shows that the model can robustly and efficiently deal with the problem of a plasma β as low as about 5 × 10−7. Therefore, the established implicit solar wind MHD model is very promising for simulating complex and strong magnetic environments.
Atomic Iron and Nickel in the Coma of C/1996 B2 (Hyakutake): Production Rates, Emission Mechanisms, and Possible Parents
Authors: Bromley S. J. , Neff B. , Loch S. D. , Marler J. P. , Országh J. , Venkataramani K. , Bodewits D. 
Published: November 2021

Abstract
Two papers recently reported the detection of gaseous nickel and iron in the comae of over 20 comets from observations collected over two decades, including interstellar comet 2I/Borisov. To evaluate the state of the laboratory data in support of these identifications, we reanalyzed archived spectra of comet C/1996 B2 (Hyakutake), one of the nearest and brightest comets of the past century, using a combined experimental and computational approach. We developed a new, many-level fluorescence model that indicates that the fluorescence emissions of Fe I and Ni I vary greatly with heliocentric velocity. Combining this model with laboratory spectra of an Fe-Ni plasma, we identified 22 lines of Fe I and 14 lines of Ni I in the spectrum of Hyakutake. Using Haser models, we estimate the nickel and iron production rates as Q
Ni = (2.6–4.1) × 1022 s−1 and Q
Fe = (0.4–2.8) × 1023 s−1. From derived column densities, the Ni/Fe abundance ratio log10[Ni/Fe] = −0.15 ± 0.07 deviates significantly from solar abundance ratios, and it is consistent with the ratios observed in solar system comets. Possible production and emission mechanisms are analyzed in the context of existing laboratory measurements. Based on the observed spatial distributions, excellent fluorescence model agreement, and Ni/Fe ratio, our findings support an origin consisting of a short-lived unknown parent followed by fluorescence emission. Our models suggest that the strong heliocentric velocity dependence of the fluorescence efficiencies can provide a meaningful test of the physical process responsible for the Fe I and Ni I emission.
Travail bénévole dans l’aide sociale et juridique aux demandeurs d’asile
Authors: Lepoutre Lucie 
Published: November 2021

Des associations sont mandatées par l’État pour réaliser un accompagnement social et juridique des demandeurs d’asile en recrutant des intervenants salariés. En parallèle, de nombreuses associations de bénévoles en France assurent la réalisation de missions similaires. À partir d’une enquête sociologique, cet article interroge la place des bénévoles dans l’aide sociale et juridique apportée aux personnes en demande d’asile. Ce travail gratuit est porteur d’un message de solidarité et d’engagement citoyen auprès des personnes migrantes. Il est aussi révélateur d’un système d’accueil sous-dimensionné qui ne parvient pas à répondre à l’ensemble des besoins. Pour les associations militantes, la gratuité est alors mobilisée comme un argument permettant de dénoncer le manque de moyens que l’État attribue à cette cause.
Primerjalno o literarni večjezičnosti v slovenskem in avstrijskem kontekstu
Authors: Žerjal Pavlin Vita 
Published: November 2021

Kritika:
Alenka Koron in Andrej Leben, ur.: Literarna večjezičnost v slovenskem in avstrijskem kontekstu. Ljubljana: Založba ZRC, 2020. (Studia litteraria 26). 324 str.
Comparison of High Resolution Ultrasonography with Clinical Examination in the Assessment of Peripheral Nerve Involvement in Leprosy
Authors: Venugopal Renu , Binesh V. G. , Puthussery Paul V. , George Sandhya , Asokan Neelakandhan 
Published: November 2021

Context:
Assessment of peripheral nerves in leprosy by clinical methods is subject to considerable inter-observer variability. High resolution ultrasonography (HRUS) can assess peripheral nerves more objectively.

Aims:
To compare the findings of peripheral nerve involvement in newly diagnosed cases of leprosy by clinical and sonological methods.

Settings and Design:
Cross sectional study in a tertiary care teaching hospital.

Subjects and Methods:
Four pairs of peripheral nerves of 40 newly diagnosed patients with leprosy were examined clinically and by HRUS.

Statistical Analysis Used:
Agreement between clinical examination and HRUS using kappa statistic; sensitivity; specificity; and predictive values.

Results:
Of the 320 nerves examined, 71 (22.18%) were abnormal clinically and 63 (19.7%) sonologically. Sonological abnormalities were increased cross sectional area (n = 63; 100%), hypoechogenicity with loss of fascicular architecture (n = 46; 73%) and increased vascularity (n = 35; 55.6%). There was moderate agreement (Cohen's K = 0.59) between clinical and sonological findings. HRUS findings were abnormal in 18 (7.2%) nerves that were clinically normal. HRUS was normal in 26 (36.6%) nerves which were clinically abnormal. Sensitivity of HRUS compared to clinical examination was 63%; specificity 92.7%; positive predictive value 71.4%; and negative predictive value 89.9%. Increased cross sectional area agreed with clinical findings the most.

Conclusions:
HRUS has low sensitivity (63%) and high specificity (92.7%) to identify abnormal peripheral nerves in leprosy, compared to clinical examination. It could detect abnormality of some (n = 18, 7.2%) clinically normal nerves, but showed normal findings of some nerves (n = 26, 36.6%), which were considered clinically abnormal.
An Investigation into Contract Cheating in Tertiary Education, and How to Combat the Problem in a United Arab Emirates Context
Authors: Pacino Andy 
Published: November 2021

This review article investigated the pervasive problem that contract cheating presents in higher education in the United Arab Emirates (UAE), and aimed to discover whether a solution could be found to combat the growing use of essay mills among students in the region. This literature review aimed to answer the following research questions; why do students use essay mills? Is current university student academic support adequate to facilitate branch campus learning at a level equivalent to a home campus? What methods can international branch campuses in the UAE employ to discourage the use of essay mills? What type and levels of services can universities provide in the future that better support students and stop them from becoming potential essay mill users? The point of the research was to find a means by which students can be dissuaded from using contract cheating sites by becoming so well-supported, and so aware of the threat that contract cheating poses to the value of their degree, that essay mills become a much less attractive option. The study began with a look into the possible circumstances that lead a student to cheat, which includes exploring the fraud triangle theory, the peer behaviour theory, the planned behaviour theory, and the subsequent methodology used. The study found a variety of reasons students cheat, citing laziness, a lack of ability or adequate depth of academic vocabulary in a second language learner, peer pressure, that it is so easy and convenient to use such sites, and the fact that there is a promise of plagiarism free work with a click of a mouse and simple financial transaction (Clarke & Lancaster, 2013). Furthermore, online contract cheating presents a significant challenge for higher education institutes to keep a check on standards and quality assurance. Many teachers are either unaware of or simply afraid to follow up on instances of contract cheating for fear of recriminations in the form of poor feedback or possible student dropout rates.
Fatalistic Views and the Impact on Combating COVID-19: Bangladesh Context
Authors: Ahmed Saifuddin , RAHMAN MD. ZARIF , Meem Mahabuba Islam 
Published: November 2021

Purpose: The main objective of this study is to evaluate whether the COVID-19 pandemic has influenced the people of Bangladesh to become more fatalistic or not.
Approach/Methodology/Design: The study is of a descriptive design. The study follows a mixed-method research approach where an online survey was conducted among 406 individuals and 15 interviews of experts in different criteria have been assembled to validate the survey results properly. This survey data were analyzed based on the age and economic condition of the respondents. The in-depth interviews were collected based on six categories: Academicians, religious scholars, medical practitioners, Coronavirus-infected individuals, law enforcement officials, and journalists.
Findings: The study shows that most of the people of Bangladesh are not influenced by the fatalistic views. The COVID-19 pandemic has certainly made people more dependent on fate lately. Senior citizens of the society and people with low income are more fatalists than other groups of people in the society. Senior citizens are suffering the most from anxiety, youths of Bangladesh are facing the most uncertainty in this pandemic. None of the population groups are completely dependent on fate yet confident about the situation at the same time.
Practical Implications: The findings of this study will pave the way forward for further research in this area and help policymakers to take necessary initiatives. In short term, it will help formulating policies for the vulnerable groups. Such as, providing economic assistance for the lowest range of income group, guaranteeing old age pension for the senior citizens, access to right information, and psychological stability. In long term, this study will allow practitioners to create awareness during disasters and pandemics through expert narratives, news, and social media awareness.
Originality/value: This paper explores how the belief system of people is influenced by their socio-economic condition and how it affects their behavior in terms of combating pandemics. It also emphasizes that during disasters and pandemics, policymakers should take special initiatives for senior citizens and people with low income.
The implications of covid-19 on the shipping/oil tanker market.
Authors: Ogoun Ogoun 
Published: November 2021

Purpose: This aims at analyzing the implications of covid-19 on the shipping/oil tanker market.
Methodology: In order to attain the aim of this study, findings and data are curated from existing literatures, documents, policies, etc. This implies that desk review is the methodology applied in this study where the researcher made use of secondary sources of data as against primary source of data.
Findings: In the study, it was found that covid-19 brought about a shortage in the rate of demands for good thereby causing an unbalance in the rate of supply over demand at a time which directly brought about a huge decline in shipping/oil tanker transportation. The study also found that irrespective of the huge decline in the rate of shipping/oil tanker transportation brought about by low demand in comparison with supply; shipping/oil tanker was patronized by dealers for the purpose of storage of products. Also, the study found that seaborne trade fell downward from above 3% to below a negative 8% and at a bdp rate of 100m, the demand was 3% higher than the global supply which in 2019 was at about 97%. However, in the second quarter of 2020 the supply leads demand at over 28M bdp and a 13% increase in the demand year-on-year when compared to a fall of 3.9% in the supply year-on-year.
Recommendation: The study recommends that appropriate forecasting methods and proper liaison with global health will aid in averting or ameliorating the risks and negative impacts brought on shipping/oil tanker market by covid-19.