bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theory of Turbulent Equilibrium Spheres with Power-law Linewidth–Size Relation
Authors: Moon Sanghyuk , Ostriker Eve C. 
Published: November 2024

Abstract
Dense cores inherit turbulent motions from the interstellar medium in which they form. As a tool for comparison to both simulations and observations, it is valuable to construct theoretical core models that can relate their internal density and velocity structure while predicting their stability to gravitational collapse. To this end, we solve the angle-averaged equations of hydrodynamics under two assumptions: (1) the system is in a quasi-steady equilibrium; (2) the velocity field consists of radial bulk motion plus isotropic turbulence, with turbulent dispersion increasing as a power law in the radius. The resulting turbulent equilibrium sphere (TES) solutions form a two-parameter family, characterized by the sonic radius r

s
and the power-law index p. The TES is equivalent to a Bonnor–Ebert (BE) sphere when r

s
→ ∞ . The density profile in the outer regions of the TES is slightly shallower than the BE sphere, but is steeper than the logotropic model. Stability analysis shows that the TESs with size exceeding a certain critical radius are unstable to radial perturbations. The center-to-edge density contrast, mass, and radius of the marginally stable TES all increase with increasing average velocity dispersion. The FWHM of the column density profile is always smaller than the critical radius, by a larger factor at higher velocity dispersion, suggesting that observations need to probe beyond the FWHM to capture the full extent of turbulent cores. When applied to the highly turbulent regime typical of cluster-forming clumps, the critical mass and radius of the TES intriguingly resembles the typical mass and radius of observed star clusters.
The First Detection of X-Ray Polarization in a Newly Discovered Galactic Transient Swift J151857.0-572147
Authors: Mondal Santanu , Suribhatla S. Pujitha , Chatterjee Kaushik , Singh Chandra B. , Chatterjee Rwitika 
Published: November 2024

Abstract
We study the spectropolarimetric properties of a newly discovered black hole (BH) X-ray binary Swift J151857.0-572147 jointly using Imaging X-ray Polarimetry Explorer (IXPE) and NuSTAR observations during 2024 March. The analysis of IXPE data reports the first detection of X-ray with a polarization degree (PD) of 1.34 ± 0.27 and a polarization angle (PA) of −13.°69 ± 5.°85 using a model-independent approach, while the model-dependent analysis gives a PD of 1.18 ± 0.23 and a PA of −14.°01 ± 5.°80. The joint spectral analysis of the broadband data and NuSTAR analysis in isolation constrain the mass of the central BH between ∼9.2 ± 1.6 and 10.1 ± 1.7M
⊙ and a moderate spin parameter of ∼0.6 ± 0.1–0.7 ± 0.2 with a disk inclination of ∼35° ± 7°–46° ± 15°. The power-law photon index and cutoff energy are 2.19 ± 0.03–2.47 ± 0.06 and ∼36 ± 4–78 ± 10 keV, suggesting a transition to the soft spectral state. Additionally, a relatively lower corona size of 6 ± 1–9 ± 2r

S
, a low mass outflow rate (

<
3
%

M

̇

Edd

), and the best-fitted halo accretion is less compared to the disk accretion rate further confirm the same state. The low PD detected in the soft state can be due to repeated scattering inside the dense corona, and the dominant emission from the disk agrees with the low spin and low disk inclination. The hydrogen column density obtained from the fit is relatively high at ∼4–5 × 1022 cm−2.
Self-similar Buildup and Inside-out Growth: Tracing the Evolution of Intermediate-to-high-mass Star-forming Galaxies since z = 2
Authors: Hasheminia Maryam , Mosleh Moein , Hosseini-ShahiSavandi S. Zahra , Tacchella Sandro 
Published: November 2024

Abstract
We aim to discern scenarios of structural evolution of intermediate-to-high-mass star-forming galaxies (SFGs) since cosmic noon by comparing their stellar mass profiles with present-day stellar masses of

log
(

M

*
,
0

/

M

⊙

)
=
10.3
−
11

. We addressed discrepancies in the size evolution rates of SFGs, which may be caused by variations in sample selection and methods for size measurements. To check these factors, we traced the evolution of individual galaxies by identifying their progenitors using stellar mass growth histories (SMGHs), integrating along the star-forming main sequence and from the IllustrisTNG simulations. Comparison between the structural parameters estimated from the mass- and light-based profiles shows that mass-weighted size evolves at a slower pace compared to light-based ones, highlighting the need to consider the mass-to-light ratio (M/L) gradients. Additionally, we observed mass-dependent growth in stellar mass profiles: massive galaxies (

log
(

M

*
,
0

/

M

⊙

)
≳
10.8

) formed central regions at z ≳ 1.5 and grew faster in outer regions, suggesting inside-out growth, while intermediate-mass and less massive SFGs followed a relatively self-similar mass buildup since z ∼ 2. Moreover, slopes of observed size evolution conflict with the predictions of TNG50 for samples selected using the same SMGHs across our redshift range. To explore the origin of this deviation, we examined changes in angular momentum (AM) retention fraction using the half-mass size evolution and employing a simple disk formation model. Assuming similar dark matter halo parameters, our calculations indicate that the AM inferred from observations halved in the past 10 Gyr while it remained relatively constant in TNG50. This higher AM in simulations may be due to the accretion of high-AM gases into disks.
CZ Aqr: An Oscillating Eclipsing Algol-type System Composed of a δ Sct Primary Star and a Subgiant Star in a Quadruple System
Authors: Zeng Qi-Huan , Liao Wen-Ping , Qian Sheng-Bang , Li Lin-Jia , Li Ping , Deng Zhao-Long 
Published: November 2024

Abstract
Eclipsing Algol-type systems containing a δ Scuti (hereafter δ Sct) star enable precise determination of physical parameters and the investigation of stellar internal structure and evolution. We present the absolute parameters of CZ Aquarius (hereafter CZ Aqr) based on TESS data. CZ Aqr has an orbital period of 0.86275209 day, a mass ratio of 0.489 (6), and the secondary component nearly fills its Roche lobe. O − C analysis reveals a downward parabolic trend and a cyclical variation with a period of 88.2 yr. The downward parabola suggests a long-term decrease in the orbital period with

P

̇

= −3.09 × 10−8 days yr−1. The mass loss rate is estimated to be 4.54 × 10−9
M
⊙ yr−1, which is possibly due to magnetic stellar wind or a hot spot. The cyclical variation might be caused by the light travel time effect via the presence of a third body with a minimum mass of

M

3
min

= 0.312 (21) M
⊙. Additionally, there are two possible celestial bodies in a 2:7 resonance orbit around CZ Aqr. The asymmetric light curve is explained by adding a hot spot on the surface of the primary star. After removing the binary model, 26 frequencies were extracted from TESS data. Two radial modes were newly identified among three possible independent frequencies. Our results show that the eclipsing Algol-type system is composed of a δ Sct primary star and a subgiant star in a quadruple system.
Parkes Radio and NuSTAR X-Ray Observations of the Composite Supernova Remnant B0453–685 in the Large Magellanic Cloud
Authors: Eagle Jordan , Hare Jeremy , Hays Elizabeth , Castro Daniel , Gelfand Joseph , Alnaqbi Jwaher , Kerr Matthew , Dai Shi , Ballet Jean , Acero Fabio , Slane Patrick , Ajello Marco 
Published: November 2024

Abstract
Gamma-ray emission is observed coincident in position to the evolved, composite supernova remnant (SNR) B0453–685. Prior multiwavelength investigations of the region indicate that the pulsar wind nebula (PWN) within the SNR is the most likely origin for the observed gamma rays, with a possible pulsar contribution that becomes significant at energies below E ∼ 5 GeV. Constraints on the PWN hard X-ray spectrum are important for the most accurate broadband representation of PWN emission and determining the presence of a gamma-ray pulsar component. The results of Parkes radio and Nuclear Spectroscopic Telescope Array (NuSTAR) X-ray observations are presented on PWN B0453–685. We perform a search for the central pulsar in the new Parkes radio data, finding an upper limit of 12 μJy. A pulsation search in the new NuSTAR observations additionally provides a 3σ upper limit on the hard X-ray pulsed fraction of 56%. The PWN is best characterized with a photon index ΓX = 1.91 ± 0.20 in the 3–78 keV NuSTAR data, and the results are incorporated into existing broadband models. Last, we characterize a serendipitous source detected by Chandra and NuSTAR that is considered a new high-mass X-ray binary candidate.
CME Velocity Field Calculation Model Based on an Unsupervised Transformer Optical Flow Network
Authors: Chen Qingyang , Lin Hong , Qiang Zhenping , Liu Hui , Ji Kaifan , Shang Zhenhong 
Published: November 2024

Abstract
The optical flow algorithm (OF) is one the main methods for calculating image velocity field and has many applications in space weather. Most OF calculations are applied to the motion of labeled rigid objects and are not suitable for velocity detection of high-energy particles, such as in a coronal mass ejection (CME). Fluctuations in exposure time and the influence of space weather will lead to inconsistent brightness of the same feature point at different times. To address this problem, we propose an unsupervised multiscale optical flow network based on Vision Transformer, named UTFlowNet. The network comprises a multiscale feature extraction module and a coarse-to-fine global optical flow calculation module. The movement of high-energy particles emitted during a CME eruption follows certain physical rules. Therefore, we apply fluid motion–based loss functions to analyze the motion of high-energy particles more effectively, addressing the problem of CME motion field extraction. Our method can be applied to the real-time automatic extraction of a CME’s velocity field and performs well with inconsistent brightness, large-scale motion, and strong CME noise. Additionally, we can estimate subpixel level fine-grained velocity. Our model may be affected by overfitting during cross–data set inference, so we encourage performing a small amount of transfer learning on new data sets to mitigate this issue. In order to verify the accuracy of our method, we conducted experiments and verification on the Solar and Heliospheric Observatory LASCO C2 data and the High Altitude Observatory MLSO data. We constructed a large-scale displacement simulation data set based on LASCO C2 data and tested on it, achieving the best results.
Rethinking the landslide risk assessment for socio-ecological systems using the example of the northern Bulgarian Black Sea coast
Authors: Frantzova Antoaneta , Ivanov Plamen , Dobrev Nikolai , Berov Boyko , Nankin Rosen , Krastanov Miroslav , Ranguelov Boyko 
Published: November 2024

In recent years, society become much more interested in nature disasters that cause damage. The consequences of these destructive processes of a meteorological, hydrological and geological nature sometimes remain for years until the affected areas are recultivated, restored and recovered. These natural processes work together, often following each other or triggering each other to create a massive system of destruction that causes a lot of damage and often leads to death and numerous casualties.
Moreover, with the changes in the global climate of the Planet, leading to the more frequent manifestation of more destructive natural phenomena - cyclones, storms, huge amounts of precipitation - lead to intensify and manifest in larger scales and volumes geological phenomena such as landslides, mudflows, mud - stone torrents, rockfalls, collapses of different character of slopes, linear and planar erosion etc.
This is extremely relevant for Bulgaria, the territory for which is no exception to the manifestation of catastrophic natural phenomena. The country is located in an active orogenic zone as part of the Alpo-Himalayan tectonic belt, characterised by a complex tectonic structure, variable and diverse geological formations and rapid topographical changes.
The main focus in the study is to present an advanced, multi-faceted framework for natural disaster risk assessment, integrating biodiversity and archaeological sites. Moreover, the assessments of natural risks made so far do not include sufficient attention to biotopes and archaeological and historical sites.
The presented methodology is applied to landslide hazards in a pre-selected area along the northern Bulgarian Black Sea coast. The main goal of this paper is to identify socio-environmental risks in the studied region, as well as to construct risk profiles and visually represent both qualitative and quantitative risk levels in the socio-ecological system and biodiversity.
Association of Social Determinants of Health With Hospital Readmission and Mortality: A Prospective Cohort Study
Authors: Mixon Amanda S. , Goggins Kathryn , Nwosu Samuel , Shi Yaping , Schildcrout Jonathan S. , Wallston Kenneth A. , Leon-Perez Gabriela , Harrell Frank E. , Bell Susan P. , Mayberry Lindsay S. , Vasilevskis Eduard E. , Schnelle John F. , Rothman Russell L. , Kripalani Sunil ,   for the Vanderbilt Inpatient Cohort Study
Published: November 2024

Background
The relative contributions of common patient-reported social determinants of health on 30- and 90-day post-discharge outcomes among patients with acute coronary syndromes (ACS) is unclear.

Objective
The aim of this article is to examine the independent associations of social determinants with readmission or death, accounting for medical history.

Methods
Participants included adults who were hospitalized with ACS at an academic medical center. Domains measured were social support, health literacy/numeracy, and socioeconomic status (SES) (including education and difficulty paying bills). We employed multivariable Cox proportional hazard models to study associations with time to all-cause readmission or death, up to 30 or 90 days after discharge, and adjusted for demographics and medical history (prior admissions and Elixhauser comorbidity index).

Key Results

Among 1,168 patients with ACS and no history of heart failure, more prior admissions, and higher comorbidity index (the medical history domain) were associated with higher rates of 30- and 90-day readmission or death (domain
p
values <.01 and <.0001, respectively). The social support domain was not associated with outcomes. Higher health literacy and numeracy were associated with lower rates of 30- and 90-day readmission or death (domain
p
values .016 and .002, respectively). Higher education and less difficulty paying bills (the SES domain) was marginally associated with lower rates of 90-day readmission or death (domain,
p
= .052).

Conclusions

In addition to medical history, the domain of health literacy and numeracy was independently associated with readmission or death of patients with ACS during the 90 days after hospital discharge. [

HLRP: Health Literacy Research and Practice
. 2024;8(4):e212–e223.

]
Enseigner les œuvres chorégraphiques. Statuts et missions des répétiteur·ices dans les compagnies classiques
Authors: Cappelle Laura 
Published: November 2024

En plus des professeur·es de danse, une autre figure tient un rôle pédagogique essentiel dans le champ chorégraphique. Les répétiteur·ices réalisent au quotidien un travail de transmission qui en fait des « passeur·ses » centraux dans les processus de répétition. À partir d’entretiens et d’observations menés auprès de plusieurs compagnies classiques internationales, les statuts variables des répétiteur·ices dans les compagnies classiques de répertoire – permanent·es, invité·es – sont présentés, ainsi que la transition progressive du métier d’interprète vers celui de répétiteur·ice qui constitue un mode privilégié d’entrée dans la carrière. Les responsabilités concrètes des répétiteur·ices en studio sont ensuite détaillées, des tâches techniques aux fonctions artistiques. Est interrogée enfin la dimension créative du travail de ces pédagogues, souvent peu reconnue, à partir d’exemples soulignant les manières dont les répétiteur·ices peuvent informer les œuvres et participer activement à l’élaboration de la chorégraphie.
Étude de l’usage des doigts en mathématiques chez des élèves présentant un trouble du développement intellectuel
Authors: Bonneton-Botté Nathalie , Ollivier Fanny , Hili Hélène , Saliot Nadège , Bonnet Benoit , Quelaudren Nolwenn , Vlieghe Delphine , Payre Hugo , Germain Anne Laure , Boivin Adrian , Jarry Sonia 
Published: November 2024

Les habiletés numériques et arithmétiques de base sont affectées chez les personnes avec déficience intellectuelle (DI). Des études récentes montrent que le recours aux doigts est une procédure qui peut faciliter la construction de ces habiletés chez les enfants au développement typique. Cette étude vise à caractériser le recours aux doigts chez les élèves avec DI lorsqu’ils ont à résoudre des petits problèmes verbaux ou avec énoncés arithmétiques. Il s’agit aussi d’étudier les relations entre certaines composantes de la motricité manuelle, le recours aux doigts et les premières habiletés numériques et de calcul. Les résultats indiquent que les élèves avec DI âgés en moyenne de 10 ans et 4 mois qui utilisent les doigts pour résoudre des problèmes arithmétiques ou avec énoncés verbaux sont plus fréquemment en réussite. Comme pour les enfants au développement typique, les différences de dextérité pourraient expliquer les différences interindividuelles de recours à cette procédure pour le calcul. Ces résultats permettent de considérer le potentiel bénéfice d’un dispositif d’enseignement explicite à l’usage des doigts en mathématiques pour des élèves présentant une déficience intellectuelle.
Dietary habits among primary school learners in the Tshwane West District of Gauteng, South Africa
Authors: Phetla Morentho C. , Skaal Linda , Chelule Kiprano P. 
Published: November 2024

Background: Poor dietary habits are major contributors to malnutrition globally, particularly in children living in African countries. The widespread transition from African diet of healthy indigenous foods to a nutrient-poor Western-style diet is well-documented in global societal culture.Aim: This study aimed to assess the dietary habits and their nutritional implications among learners in public primary schools.Setting: City of Tshwane, located in the Gauteng province of South Africa.Methods: This was a quantitative cross-sectional study where researcher-administered questionnaire was used to collect data from 814 primary school learners in grades 4–7. Anthropometric data were also collected. The study was conducted in 10 primary schools in the City of Tshwane.Results: Unhealthy dietary practices were observed where consumption of refined carbohydrates, sugar-filled beverages and limited protein was prevalent. The prevalence rates for overweight and obesity were 15.1% and 11.3%, respectively. Most learners (77.4%) purchased foods from street vendors and tuckshops. Also, learners who knew about healthy eating were less likely to be underweight than those who did not (OR: 0.35; 95% CI: 0.14–0.85; p = 0.020).Conclusion: Poor dietary habits are demonstrated in this study and may be associated with the rising levels of overweight and obesity among the learners. The findings also showed that the school environment is the main source of exposure to unhealthy diet.Contribution: Intervention strategies, such as amendment of the national school nutrition policy, need to be implemented.
The contributions of Enactus to South Africa’s Social and Solidarity Economy: A case study of a University
Authors: Ndlovu Crespen , Lefera Maraka 
Published: November 2024

Background: Over the past decade, there has been a noticeable rise in worldwide acknowledgement of the Social and Solidarity Economy (SSE) and its substantial socioeconomic and environmental benefits. In response, the United Nations General Assembly (UNGA) passed a resolution on 18 April 2023 advocating for government and institutional support to the SSE towards accelerating the achievement of sustainable development Goals (SDGs). However, there is a lack of understanding of how higher education institutions contribute to this agenda.Aim: The study examines the contributions of Entrepreneurial Action Us (Enactus) to South Africa’s SSE.Setting: The case study was conducted at the Central University of Technology (CUT), Free State in South Africa, to examine how higher education and the SSE interact through Enactus initiatives.Methods: The study utilised a qualitative research design involving semi-structured interviews with 11 students and alumni and an analysis of Enactus’ annual impact reports. This allowed for a comprehensive understanding of participants’ experiences and perceptions regarding Enactus’ impact on the SSE.Results: Enactus enhances student entrepreneurship and innovation, promoting economic growth, job creation and community sustainability. Initiatives like the student-led Vermi Village Enterprise have empowered youth and women and created employment opportunities. Collaboration with local corporations and educational institutions has fostered sustainable changes, improving regenerative agriculture and urban food production, thus addressing multiple poverty facets.Conclusion: This study highlights the crucial role of initiatives like Enactus in promoting a more inclusive and sustainable economy, advancing the broader objectives of the SDGs, and supporting a brighter future for South Africa.Contribution: Despite resource limitations and the need for greater stakeholder engagement, Enactus projects and enterprises hold significant potential for driving sustainable development and socioeconomic equality, ultimately strengthening South Africa’s SSE.
Empowering South African educators: Navigating the challenges of digital teaching and learning competencies
Authors: Nyathi Trinity , Joseph Renjini M. 
Published: November 2024

Orientation: Public basic education institutions in South Africa are presently enduring new challenges about the implementation of digital teaching and learning in the absence of the digital competence required.Research purpose: The purpose of the current study was to identify the digital competencies required by educators to effectively implement digital teaching and learning interventions in basic education institutions.Motivation for the study: By identifying the digital competencies required by educators and exploring the gap in educators’ digital competence, institutions can plan and implement digital learning interventions designed for effective teaching and learning.Research approach/design and method: Semi structured interviews were conducted with a sample of 20 participants working in various positions at two secondary schools in Gauteng.Main findings: The findings showed that while some training is offered, educators lack the necessary competencies to effectively enforce digital learning interventions. This may be because of limited training, the absence of digital resources and the insufficient digital competence of educators.Practical/managerial implications: Ongoing training is mandatory to ensure that the digital competence of educators is in line with the dynamic world of work and to close the digital skills gap in teaching. Secondary school educators require assistance from the Department of Basic Education to enable the transition from traditional teaching and learning to digital praxis, through the provision of necessary digital intervention resources.Contribution/value-add: The findings make a practical contribution by offering organisations practical information on the development of digital competencies in secondary education settings.