bluuebunny/crossref_metadata_2025_split huggingface dataset:
Infrared H2O Absorption in Massive Protostars at High Spectral Resolution: Full Spectral Survey Results of AFGL 2591 and AFGL 2136
Authors: Barr Andrew G. , Boogert Adwin , Li Jialu , DeWitt Curtis N. , Montiel Edward , Richter Matthew J. , Indriolo Nick , Pendleton Yvonne , Chiar Jean , M. Tielens Alexander G. G. 
Published: August 2022

Abstract
We have performed a high-resolution 4–13 μm spectral survey of the hot molecular gas associated with the massive protostars AFGL 2591 and AFGL 2136. Here we present the results of the analysis of the ν
2 band of H2O, detected with the Echelon Cross Echelle Spectrograph on board the Stratospheric Observatory for Infrared Astronomy between wavelengths of 5 and 8 μm. All lines are seen in absorption. Rotation diagrams indicate that the gas is optically thick and lines are observed to saturate at 40% and 15% relative to the continuum for AFGL 2136 and AFGL 2591, respectively. We applied two curve of growth analyses to derive the physical conditions, one assuming a foreground origin and one a circumstellar disk origin. We find temperatures of 400–600 K. A foreground origin would require the presence of externally heated clumps that are smaller than the continuum source. The disk analysis is based on stellar atmosphere theory, which takes into consideration the temperature gradient in the disk. We discuss the challenges with each model, taking into consideration the properties of other species detected in the spectral survey, and conclude that further modeling efforts are required to establish whether the absorption has a disk or foreground origin. The main challenge to the foreground model is that molecules are expected to be observed in emission. The main challenges to the disk model are the midplane heating mechanism and the presence of narrow absorption lines shifted from the systemic velocity.
Magnetohydrodynamic Modeling Investigations of Kelvin–Helmholtz Instability and Associated Magnetosonic Wave Emission along Coronal Mass Ejections
Authors: Butler Sara , Chen Weiru , Turkakin Hava 
Published: August 2022

Abstract
Previous studies have suggested that the Kelvin–Helmholtz instability (KHI) and magnetohydrodynamic (MHD) wave emissions via the KHI along various shear flow boundaries in a solar–terrestrial environment may be possible. We expand upon these previous studies to investigate the linear and nonlinear evolution of the KHI and emission of MHD waves along the boundaries of coronal mass ejections (CMEs). Our results demonstrate that the KHI and MHD wave emission due to the KHI are possible along the CME boundaries during the KHI development. We found that magnetic field orientation in the region outside of the CME has strong effects on the strength of MHD wave emission. While a smaller parallel component of the magnetic field resulted in larger growth rates in the KHI development, a larger parallel component of the magnetic field resulted in stronger MHD wave emissions. For all cases we investigated, we identified emitted waves to be fast MHD waves. We suggest that these emitted MHD waves may be able to carry available kinetic energy from the CME flow to the outside of the CME, thereby contributing to solar coronal heating via energy dissipation.
Hard X-Ray Emission from the Eastern Jet of SS 433 Powering the W50 “Manatee” Nebula: Evidence for Particle Reacceleration
Authors: Safi-Harb Samar , Mac Intyre Brydyn , Zhang Shuo , Pope Isaac , Zhang Shuhan , Saffold Nathan , Mori Kaya , Gotthelf Eric V. , Aharonian Felix , Band Matthew , Braun Chelsea , Fang Ke , Hailey Charles , Nynka Melania , Rho Chang D. 
Published: August 2022

Abstract
We present a broadband X-ray study of W50 (the “Manatee” nebula), the complex region powered by the microquasar SS 433, that provides a test bed for several important astrophysical processes. The W50 nebula, a Galactic PeVatron candidate, is classified as a supernova remnant but has an unusual double-lobed morphology likely associated with the jets from SS 433. Using NuSTAR, XMM-Newton, and Chandra observations of the inner eastern lobe of W50, we have detected hard nonthermal X-ray emission up to ∼30 keV, originating from a few-arcminute-sized knotty region (“Head”) located ≲18′ (29 pc for a distance of 5.5 kpc) east of SS 433, and constrained its photon index to 1.58 ± 0.05 (0.5–30 keV band). The index gradually steepens eastward out to the radio “ear” where thermal soft X-ray emission with a temperature kT ∼ 0.2 keV dominates. The hard X-ray knots mark the location of acceleration sites within the jet and require an equipartition magnetic field of the order of ≳12 μG. The unusually hard spectral index from the “Head” region challenges classical particle acceleration processes and points to particle injection and reacceleration in the subrelativistic SS 433 jet, as seen in blazars and pulsar wind nebulae.
GaMPEN: A Machine-learning Framework for Estimating Bayesian Posteriors of Galaxy Morphological Parameters
Authors: Ghosh অরিত্র Aritra ঘোষ , Urry C. Megan , Rau Amrit , Perreault-Levasseur Laurence , Cranmer Miles , Schawinski Kevin , Stark Dominic , Tian 田 Chuan 川 , Ofman Ryan , Ananna Tonima Tasnim , Auge Connor , Cappelluti Nico , Sanders David B. , Treister Ezequiel 
Published: August 2022

Abstract
We introduce a novel machine-learning framework for estimating the Bayesian posteriors of morphological parameters for arbitrarily large numbers of galaxies. The Galaxy Morphology Posterior Estimation Network (GaMPEN) estimates values and uncertainties for a galaxy’s bulge-to-total-light ratio (L

B
/L

T
), effective radius (R

e
), and flux (F). To estimate posteriors, GaMPEN uses the Monte Carlo Dropout technique and incorporates the full covariance matrix between the output parameters in its loss function. GaMPEN also uses a spatial transformer network (STN) to automatically crop input galaxy frames to an optimal size before determining their morphology. This will allow it to be applied to new data without prior knowledge of galaxy size. Training and testing GaMPEN on galaxies simulated to match z < 0.25 galaxies in Hyper Suprime-Cam Wide g-band images, we demonstrate that GaMPEN achieves typical errors of 0.1 in L

B
/L

T
, 0.″17 (∼7%) in R

e
, and 6.3 × 104 nJy (∼1%) in F. GaMPEN's predicted uncertainties are well calibrated and accurate (<5% deviation)—for regions of the parameter space with high residuals, GaMPEN correctly predicts correspondingly large uncertainties. We also demonstrate that we can apply categorical labels (i.e., classifications such as highly bulge dominated) to predictions in regions with high residuals and verify that those labels are ≳97% accurate. To the best of our knowledge, GaMPEN is the first machine-learning framework for determining joint posterior distributions of multiple morphological parameters and is also the first application of an STN to optical imaging in astronomy.
A Comprehensive Analysis of the Gravitational Wave Events with the Stacked Hilbert–Huang Transform: From Compact Binary Coalescence to Supernova
Authors: Hu Chin-Ping , Lin Lupin Chun-Che , Pan Kuo-Chuan , Li Kwan-Lok , Yen Chien-Chang , Kong Albert K. H. , Hui C. Y. 
Published: August 2022

Abstract
We analyze the gravitational wave signals with a model-independent time-frequency analysis, which is improved from the Hilbert–Huang transform (HHT) and optimized for characterizing the frequency variability on the time-frequency map. Instead of the regular HHT algorithm, i.e., obtaining intrinsic mode functions with ensemble empirical mode decomposition and yielding the instantaneous frequencies, we propose an alternative algorithm that operates the ensemble mean on the time-frequency map. We systematically analyze the known gravitational wave events of the compact binary coalescence observed in the first gravitational-wave transient catalog, and in the simulated gravitational wave signals from core-collapse supernovae (CCSNe) with our method. The time-frequency maps of the binary black hole coalescence cases show much more detail compared to those wavelet spectra. Moreover, the oscillation in the instantaneous frequency caused by mode-mixing could be reduced with our algorithm. For the CCSNe data, the oscillation from the proto-neutron star and the radiation from the standing accretion shock instability can be precisely determined with the HHT in great detail. More importantly, the initial stage of different modes of oscillations can be clearly separated. These results provide new hints for further establishment of the detecting algorithm and new probes to investigate the underlying physical mechanisms.
Modeling the Gamma-Ray Burst Jet Properties with 3D General Relativistic Simulations of Magnetically Arrested Accretion Flows
Authors: James Bestin , Janiuk Agnieszka , Nouri Fatemeh Hossein 
Published: August 2022

Abstract
We investigate the dependence of the gamma-ray burst (GRB) jet structure and its evolution on the properties of the accreting torus in the central engine. Our models numerically evolve the accretion disk around a Kerr black hole using three-dimensional general relativistic magnetohydrodynamic simulations. We use two different analytical hydrodynamical models of the accretion disk, based on the Fishbone–Moncrief and Chakrabarti solutions, as our initial states for the structure of the collapsar disk and the remnant after a binary neutron star (BNS) merger, respectively. We impose poloidal magnetic fields of two different geometries upon the initial stable solutions. We study the formation and evolution of the magnetically arrested disk state and its effect on the properties of the emitted jet. The jets produced in our models are structured and have a relatively hollow core and reach higher Lorentz factors at an angle ≳9° from the axis. The jet in our short GRB model has an opening angle of up to ∼25° while our long GRB engine produces a narrower jet, of up to ∼11°. We also study the time variability of the jets and provide an estimate of the minimum variability timescale in our models. The application of our models to the GRB jets in the BNS postmerger system and to the ultrarelativistic jets launched from collapsing stars are briefly discussed.
Timing Properties of the X-Ray Accreting Pulsar 1A 0535+262 Studied with Insight-HXMT
Authors: Wang P. J. , Kong L. D. , Zhang S. , Doroshenko V. , Santangelo A. , Ji L. , Yorgancioglu E. S. , Chen Y. P. , Zhang S. N. , Qu J. L. , Ge M. Y. , Li J. , Chang Z. , Tao L. , Peng J. Q. , Shui Q. C. 
Published: August 2022

Abstract
We report results on the timing analysis of the 2020 giant outburst of 1A 0535+262, using broadband data from Insight-HXMT. The analysis of the pulse profile evolution from the subcritical-luminosity to the supercritical-luminosity regime is presented for the first time. We found that the observed pulse profile exhibits a complex dependence on both energy and luminosity. A dip structure at the energy of the cyclotron resonant scattering features is found for the first time in the pulse fraction–energy relation of 1A 0535+262, when the outburst evolves in a luminosity range from 4.8 × 1037 to 1.0 × 1038 erg s−1. The observed structure is luminosity dependent and appears around the source critical luminosity (∼6.7 × 1037 erg s−1).
GRB 201104A: A “Repetitive” Short Gamma-Ray Burst?
Authors: Wang Yun , Jiang Lu-Yao , Ren Jia 
Published: August 2022

Abstract
Gamma-ray bursts (GRBs) are divided into short gamma-ray bursts (SGRBs) and long gamma-ray bursts (LGRBs) based on the bimodal distribution of their durations. LGRBs and SGRBs are typically characterized by different statistical characteristics. Nevertheless, there are some samples that challenge such a framework, such as GRB 060614, a long-duration burst with short-burst characteristics. Furthermore, GRBs are generally considered to be an event with no periodic or repetitive behavior, since the progenitors usually undergo destructive events, such as massive explosions or binary compact star mergers. In this work, we investigated Fermi data for possible quasiperiodic oscillations and repetitive behaviors of GRBs using timing analysis methods and report a special event GRB 201104A, which is a long-duration burst with the characteristics of an SGRB, and it exhibits a “repetitive” behavior. We propose that such a situation may arise from lensed SGRBs and attempt to verify it by Bayesian inference. In addition, we extend the spectral analysis to Bayesian inference. In spite of the existence of at least two distinct time periods with a nearly identical spectrum, there is no strong evidence that they result from a lensing GRB. Taking the gravitational-lensing scenario out of consideration, a long burst would resemble a short burst in its repetitive behavior, which presents a challenge for the current classification scheme.
An Atlas of Convection in Main-sequence Stars
Authors: Jermyn Adam S. , Anders Evan H. , Lecoanet Daniel , Cantiello Matteo 
Published: August 2022

Abstract
Convection is ubiquitous in stars and occurs under many different conditions. Here we explore convection in main-sequence stars through two lenses: dimensionless parameters arising from stellar structure and parameters that emerge from the application of mixing length theory. We first define each quantity in terms familiar to both the 1D stellar evolution community and the hydrodynamics community. We then explore the variation of these quantities across different convection zones, different masses, and different stages of main-sequence evolution. We find immense diversity across stellar convection zones. Convection occurs in thin shells, deep envelopes, and nearly spherical cores; it can be efficient or inefficient, rotationally constrained or not, transsonic or deeply subsonic. This atlas serves as a guide for future theoretical and observational investigations by indicating which regimes of convection are active in a given star, and by describing appropriate model assumptions for numerical simulations.
Penser le développement comme un mythe : croyances, engagements et (in)cohérences de l’engagement coopératif au Chiapas (Mexique)
Authors: Parizet Raphaëlle 
Published: August 2022

Cet article se penche sur le cas d’une coopérative de développement agricole réunissant des producteurs indiens de café dans la région du Chiapas au Mexique, initiée par la mission jésuite, et le confronte à l’analyse de G. Rist qui attribue au développement une direction unique et une irréversibilité. En s’appuyant sur les travaux de P. Veyne, l’article propose au contraire un réenchantement mythique du développement : ce qui est central ici, c’est la plasticité et la complexité des régimes de croyances – applaudir la coopérative n’est pas nécessairement l’ovationner. À partir d’une analyse processuelle de l’engagement, l’article cherche à comprendre les raisons d’entrée et de maintien des agriculteurs dans la coopérative. Les croyances des coopérateurs ne sont pas toutes alignées, elles s’ajustent, se contredisent et n’ont pas besoin d’être valides pour opérer. L’irréductible externalité, l’existence de figures tutélaires et d’expériences sociales partagées s’articulent à des nécessités économiques, des chevauchements de sociabilité et de solidarité, l’ensemble faisant tenir un passé collectif marqué par des conflits, des déceptions militantes et des trajectoires individuelles d’engagement.
Computability Theory
Authors: Brattka Vasco , Greenberg Noam , Kalimullin Iskander , Soskova Mariya 
Published: August 2022

Over the last decade computability theory has seen many new and fascinating developments that have linked the subject much closer to other mathematical disciplines inside and outside of logic. This includes, for instance, work on enumeration degrees that has revealed deep and surprising relations to general topology, the work on algorithmic randomness that is closely tied to symbolic dynamics and geometric measure theory. Inside logic there are connections to model theory, set theory, effective descriptive set theory, computable analysis and reverse mathematics. In some of these cases the bridges to seemingly distant mathematical fields have yielded completely new proofs or even solutions of open problems in the respective fields. Thus, over the last decade, computability theory has formed vibrant and beneficial interactions with other mathematical fields.
The goal of this workshop was to bring together researchers representing different aspects of computability theory to discuss recent advances, and to stimulate future work.
Screen Time and Health Disturbances during the Covid-19 Pandemic: A Case of University Students in Zimbabwe
Authors: Nhatuve Diocleciano , Wayne Madzokere Amanda 
Published: August 2022

This study sought to establish health disturbances experienced by university students due to prolonged screen use during the covid-19 Pandemic in Zimbabwe. It employed the descriptive design under the quantitative approach. The study involved students from two universities in Zimbabwe, and it used a random sampling technique. A total of 128 students participated completing a survey. Data collection was conducted through a survey with a one closed-ended question seeking to identify health challenges experienced by students due to prolonged use of screens. Results were presented in percentages through graphs. The study concludes that headaches, tiredness and difficulties to sleep were experienced by students as a consequence of prolonged screen time. Furthermore, students experienced different psychological disturbances including stress and depression, inattention (difficulties to concentrate), anxiety and low self-esteem as a consequence of prolonged screen time. Finally, sight loss, tearing eyes, eye irritation, eye redness, eye swelling and dry eye disease were experienced by respondents. Based on the conclusions, the study recommends that students and all users of digital technologies for different purposes should control the time they spend on the screen and visit doctors whenever they have abnormal experience in their eyes for further guidance. The study further recommends that learning institution should come up with measures to reduce the time individuals spend on the screen by providing alternative study options that may reduce the time spent on screens for learning.
Education and the Scourge of Child Marriages in Chegutu Urban and Peri-urban Clusters of Zimbabwe
Authors: Samkange Wellington 
Published: August 2022

This study sought to establish factors that contributed to child marriages in two Chegutu urban and peri-urban clusters of Zimbabwe. It used the mixed research method and the descriptive survey design. Five primary schools and five secondary schools were purposively sampled out of a total of forty schools in the clusters. Two hundred stakeholders were randomly selected from a population of one thousand five hundred. A questionnaire and interviews were used to collect data from selected school heads, teachers, parents, school development committee members and community leaders. The study established that poverty, socio-economic background, society’s perception of marriage, cultural values, lack of information and religion remain major drivers of child marriages. At the same time, the school curriculum did not fully address the issues of children’s rights and health education. The study recommends a radical approach to ending child marriages which may include banning religious sects and traditional practices that promote child marriages. It further recommends an improvement of the school curriculum, for it to take the issue of children’s rights and health education seriously.
America or India: Identifying a Suitable Off-Grid Rural Electrification Model for Nigeria.
Authors: Herbert Eti Best 
Published: August 2022

Most Nigerian living in the rural areas lack access to electricity due to lack of connectivity to the national grid network. The national grid expansion strategy to rural areas has not yielded much result due to financing and centralised approach. Off-grid electricity is considered more suitable for rapid electrification of rural areas. This paper examined the American and Indian approach to rural electrification and derived suitable lessons for Nigeria. While America ensured a robust national grid network to service rural areas, India adopted the renewable energy based off-grid options, thereby becoming the fastest developing country in rural electrification.
Keywords: Rural Electrification; Off-grid, National Grid; Renewable Energy; Financing; Decentralisation
Chrysoeriol alleviated inflammation in infantile pneumonia by inhibiting PI3K/AKT/mTOR signaling pathway
Authors: Wang Yan , Hong Qiuyue 
Published: August 2022

Purpose: To assess the therapeutic effects of chrysoeriol (CHE) on pediatric pneumonia and determine the mechanism of action.
Methods: The role of chrysoeriol was investigated in a human lung fibroblasts (HFL1) cell model of pneumonia. The effects of lipopolysaccharide (LPS) and CHE on cell viability and apoptosis were determined by CCK-8 kit and flow cytometry, respectively, while oxidative stress was determined by evaluating the levels of superoxide dismutase (SOD), glutathione, r-glutamyl cysteine +glycine (GSH)- px, myeloperoxidase (MPO) and malondialdehyde (MDA). Inflammatory response was assessed by determining IL-1β, TNF-α, IL-18 and IL-10 levels using enzyme-linked immunosorbent assay (ELISA). The mechanisms of action of CHE were evaluated by immunoblot assays.
Results: Chrysoeriol increased the viability of LPS-induced pneumonia cells (p < 0.001) but decreased cell apoptosis (p < 0.001). Furthermore, chrysoeriol reduced oxidative stress and inflammation in LPSinduced pneumonia cells, and suppressed the activation of PI3K/AKT/mTOR pathway.
Conclusion: Chrysoeriol alleviates inflammation of infantile pneumonia by inhibiting PI3K/ AKT /mTOR signaling pathway. Thus, CHE is a potential drug for the management of pneumonia.
Keywords: Chrysoeriol; Pneumonia; Cell viability; Oxidative stress; PI3K/AKT/mTOR pathway
IRF2BP2 attenuates gestational diabetes mellitus by activating AMPK signaling
Authors: Zhang Shuyun , Wang Yunjie , Zhou Ling , Yu Ziyang , Gao Aihua 
Published: August 2022

Purpose: To investigate the role of interferon regulatory factor 2 binding protein 2 (IRF2BP2) in gestational diabetes mellitus (GDM).
Methods: Mice were injected intraperitoneally with streptozotocin to establish a model of GDM and then subjected to intraperitoneal glucose tolerance test (IPGTT) and intraperitoneal insulin tolerance test (IPITT) to determine glucose and insulin tolerances. Lipid metabolism was evaluated by enzyme-linked immunosorbent assay (ELISA). The histomorphology of pancreatic islets was assessed by hematoxylin and eosin staining.
Results: IRF2BP2 was downregulated in pancreatic tissues of mice with GDM (p < 0.001). Mice in GDM group showed higher blood glucose levels than those in normal pregnancy group. However, overexpression of IRF2BP2 reduced glucose and insulin levels in mice with GDM. Overexpression of IRF2BP2 increased the level of high-density lipoprotein (HDL) and reduced triglyceride (TG), total cholesterol (TC), and low-density lipoprotein (LDL) levels in mice with GDM (p < 0.001). The histopathological changes in the islets of mice with GDM were also ameliorated by overexpression of IRF2BP2. Overexpression of IRF2BP2 reduced IL-6, IL-1β, and TNF-α levels and increased protein expression of p-AMPK in mice with GDM.
Conclusion: IRF2BP2 ameliorates the outcomes of GDM and suppressed inflammation in mice with GDM through activation of AMPK signaling. Thus, IRF2BP2 is a potential therapeutic strategy for the management of GDM.
Keywords: IRF2BP2; inflammation; gestational diabetes mellitus; AMPK; mice; insulin tolerance