bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of turbulence in high-mass star formation: Subsonic and transonic turbulence are ubiquitously found at early stages
Authors: Wang Chao , Wang Ke , Xu Feng-Wei , Sanhueza Patricio , Liu Hauyu Baobab , Zhang Qizhou , Lu Xing , Fontani F. , Caselli Paola , Busquet Gemma , Tan Jonathan C. , Li Di , Jackson J. M. , Pillai Thushara , Ho Paul T. P. , Guzmán Andrés E. , Yue Nannan 
Published: October 2023

Context. Traditionally, supersonic turbulence is considered to be one of the most likely mechanisms slowing the gravitational collapse in dense clumps, thereby enabling the formation of massive stars. However, several recent studies have raised differing points of view based on observations carried out with sufficiently high spatial and spectral resolution. These studies call for a re-evaluation of the role turbulence plays in massive star-forming regions.
Aims. Our aim is to study the gas properties, especially the turbulence, in a sample of massive star-forming regions with sufficient spatial and spectral resolution, which can both resolve the core fragmentation and the thermal line width.
Methods. We observed NH3 metastable lines with the Very Large Array (VLA) to assess the intrinsic turbulence.
Results. Analysis of the turbulence distribution histogram for 32 identified NH3 cores reveals the presence of three distinct components. Furthermore, our results suggest that (1) sub- and transonic turbulence is a prevalent (21 of 32) feature of massive star-forming regions and those cold regions are at early evolutionary stage. This investigation indicates that turbulence alone is insufficient to provide the necessary internal pressure required for massive star formation, necessitating further exploration of alternative candidates; and (2) studies of seven multi-core systems indicate that the cores within each system mainly share similar gas properties and masses. However, two of the systems are characterized by the presence of exceptionally cold and dense cores that are situated at the spatial center of each system. Our findings support the hub-filament model as an explanation for this observed distribution.
Forming merging double compact objects with stable mass transfer
Authors: Picco A. , Marchant P. , Sana H. , Nelemans G. 
Published: October 2023

Context. Merging double compact objects (COs) are one of the possible endpoints of the evolution of stellar binary systems. As they represent the inferred sources of every detected gravitational wave (GW) signal, modeling their progenitors is of paramount importance both to gain a better understanding of gravitational physics and to constrain stellar evolution theory.
Aims. Stable mass transfer (MT) between a donor star and a black hole (BH) is one of the proposed tightening mechanisms to form binary BHs that merge within the lifetime of the universe. We aim to assess the potential of stable non-conservative MT to produce different pairings of compact objects including BHs, neutron stars (NSs) and white dwarfs (WDs).
Methods. We investigated the conditions (orbital periods and mass ratios) required for MT between a star and a CO to be stable and to lead to binary COs that merge within a Hubble time. We use published results on the response of the stellar radii to rapid mass loss, covering different evolutionary stages and masses. Coupled with analytical models of orbital evolution, we determined the boundary for unstable MT as well as the post-interaction properties of binaries undergoing stable MT. In addition, we investigated the impact of the angular momentum loss prescription in the resulting hardening by accounting for both the isotropic re-emission from the accretor’s vicinity and mass outflow from the second Lagrangian point.
Results. Stable MT in systems with a CO + Roche lobe-filling star, in the completely non-conservative limit of isotropic re-emission from the vicinity of the accretor, is shown to be able to form any pair of merging double COs, with the exception of WD + BH and with a limited parameter space for NS + NS. Considering the possibility of mass outflow from the Lagrangian point L2, the resulting parameter space for GW progenitors is shifted toward smaller initial mass ratios (defined as the ratio of the donor mass over the CO mass), consequently ruling out the formation of NS + NS pairs while allowing the production of merging WD + BH binaries. We compare our results with observations of single-degenerate binaries and find that the conditions for the stable MT channel to operate are present in nature. We then show that stable MT in the isotropic re-emission channel can produce merging binary BHs with mass ratios > 0.1, consistent with the majority of inferred sources of the third gravitational wave transient catalogue. Enhanced angular momentum loss from L2 increases the minimum final mass ratio achievable by stable MT.
Assessing the Level of Evidence of Presented Studies at the Brazilian Congress of Coloproctology
Authors: Samartine Junior Hugo , Mazzini Lucas Rosasco , Paiva Daniel Ferreira , Levy Nicole Goldenberg , Silva Lauro Igor , de Aquino José Luís Braga , Mendes Elisa Donalisio Teixeira 
Published: October 2023

Abstract
Introduction Scientific studies in Brazil grew around 10.7% compared to previous years. However, the level of quality of evidence has been decreasing. The aim in our study is to examine the meeting abstracts of the Brazilian congress of coloproctology and analyze the level of evidence in trends and variables.
Methods A descriptive bibliometric study, working with secondary data to review scientific abstracts in the annals of the coloproctology congress from 2015 to 2019.
Results A total of 1756 abstracts of the Brazilian Congress of Coloproctology were analyzed for 5 years (2015-2019). There was a higher trend of abstracts presented with lower levels of evidence (level of evidence 5: 52.3% and 3: 30%), being the majority composed of case reports (49.4%) and retrospective studies (30.4%). The last two years analyzed (2018: 55.2% and 2019: 59.3%) had a predominance above average of case reports. From 2017 to 2019 there was a significant decrease in the number of level 2 evidence studies (18.10%,11.80% and 5.50%), while the number of studies with level 5 evidence showed an increase (45.60%, 56.60% and 61.40%). Statistical analysis occurred in only 17%, with an important decrease for the last two years (2018: 13.6%; 2019: 12.1%).
Conclusions Although the data of this study is from the Brazilian coloproctology point of view, they are important for the global scientific community, as they allow a quantitative evaluation of the relative contribution from the level of evidence of Brazilian coloproctology researchers to the scientific scenario.
Slovak MPs’ response to the 2022 Russian invasion of Ukraine in light of conspiracy theories and the polarization of political discourse
Authors: Lintner Tomáš , Diviák Tomáš , Nekardová Barbora , Lehotský Lukáš , Vašečka Michal 
Published: October 2023

AbstractThe 2022 Russian invasion of Ukraine received widespread international condemnation. In Slovakia, the invasion became a subject of much political discussion with large number of MPs openly advocating Russian interests. This study investigates Slovak political discourse on Facebook in the weeks before and after the invasion began. We examine the discourse through the lens of Discourse Network Analysis, combining qualitative content analysis of MPs’ Facebook posts with quantitative bipartite social network analysis. During the two weeks, we retrieved all (n = 1880) posts from all (n = 117) MPs who had an active public Facebook page. We manually coded all posts and created a bipartite discourse network consisting of MPs connected to each other via shared discourse codes in two timepoints. We performed a series of exploratory analyses that identified the content of the political discourse, the structure of the political discourse network, and the mechanisms driving the change of the political discourse network. Our results show that the invasion dramatically changed political discourse in Slovakia, with the domestic coalition-opposition struggles losing prominence among the invasion-related topics. The structure of the political discourse network showed a strong coalition-opposition split. While coalition MPs had largely pro-Ukrainian sentiments, opposition MPs largely communicated pro-Russian propaganda. A cluster of opposition MPs consistently spread conspiracy theories both before and after the invasion began, supporting a “conspiracy singularity” theory—the tendency of actors to spread multiple different conspiracy theories and interconnect various conspiracy theories into one overarching narrative. The change of the discourse network at the beginning of the invasion was largely driven by the agenda setting of several parties, agenda reinforcement, and increasing political polarization. We discuss our findings in relation to the previous research on the spread of conspiracy theories among politicians and the polarization of political discourse during the invasion, and we suggest implications for future research.
Charting the path towards a long-term knowledge brokerage function: an ecosystems view
Authors: Krystallis Ilias , Jasim Sarah 
Published: October 2023

AbstractHybrid networks of actors such as policymakers, funders, scholars, and business practitioners are simultaneous producers and consumers of evidence use. While this diversity of evidence use is a strength, it also necessitates greater collaboration among interested parties for knowledge exchange. To address this need, we investigate how ecotones, which are hybrid networks operating in the transitional area between two distinct ecosystems, such as academic research and policy ecosystems, must involve, disseminate, and integrate different types of knowledge. Specifically, our research aims to unpack how an ecotone’s knowledge brokerage function evolves over its lifecycle. This paper presents the findings of a phenomenological investigation involving experts from the policy and academic research ecosystems. The study introduces a three-stage maturity transitions framework that outlines the trajectory of the brokerage function throughout the ecotone’s lifecycle: i. as a service function, ii. a programme-partnership, and iii. a network of networks. The paper contributes to the theory of knowledge brokerage for policy-making. We reflect on our findings and discuss the theoretical contributions within an ecosystem approach and their associated research and policy implications.
The Clinician’s Role in Managing Safety during Animal-Assisted Psychotherapy
Authors: Chassman Craddock Linda 
Published: October 2023

Abstract
In this case study, I explore some of the challenges in determining which animal or animal species to choose for an animal-assisted psychotherapy (AAP) intervention. While dogs make excellent introductory animals, prey animals can offer a greater challenge and hence potential growth experience for clients. Animal choice depends on an array of factors including the client’s ability to engage safely with the animal, the treatment goal, and most importantly, the animal’s well-being and willingness to engage. To help ensure animal welfare, I detail how to mitigate the welfare challenges for humans and animals and provide examples of ways to interrupt potentially harmful behavior. A table is provided to assist with choosing an appropriate animal for different client populations.

Information
© The Author 2023
Co-Creation and Developing the Creative Economy: The ‘Galo da Madrugada’ Case
Authors: Almeida Larissa , Bakas Fiona Eva 
Published: October 2023

Summary
This case study explores the potential of connecting the creative economy with tourism through the analysis of the collaborative creative process, to rethink a carnival icon called ‘Galo de Madrugada’ (Morning Rooster) in Recife, Brazil. The icon already existed but the process by which it used to be created was not collaborative and caused few and temporary impacts. Via the description of the new creative process of the ‘Galo de Madrugada’, which brings together people from various cities in Pernambuco state, the case study illustrates how awareness for sustainable consumption is increased, which simultaneously acts as a tool to build capacity in local communities, create meaningful connections and boost social cohesion via co-working opportunities.

Information
© The Authors 2023
Exact quantisation of U(1)3 quantum gravity via exponentiation of the hypersurface deformation algebroid
Authors: Thiemann T 
Published: October 2023

Abstract
The U(1)3 model for 3+1 Euclidian signature general relativity (GR) is an interacting, generally covariant field theory with two physical polarisations that shares many features of Lorentzian GR. In particular, it displays a non-trivial realisation of the hypersurface deformation algebroid with non-trivial, i.e. phase space dependent structure functions rather than structure constants. In this paper we show that the model admits an exact quantisation. The quantisation rests on the observation that for this model and in the chosen representation of the canonical commutation relations the density unity hypersurface algebra can be exponentiated on non-degenerate states. These are states that represent a non-degenerate quantum metric and from a classical perspective are the relevant states on which the hypersurface algebra is representable. The representation of the algebra is exact, with no ambiguities involved and anomaly free. The quantum constraints can be exactly solved using groupoid averaging and the solutions admit a Hilbert space structure that agrees with the quantisation of a recently found reduced phase space formulation. Using the also recently found covariant action for that model, we start a path integral or spin foam formulation which, due to the Abelian character of the gauge group, is much simpler than for Lorentzian signature GR and provides an ideal testing ground for general spin foam models. The solution of U(1)3 quantum gravity communicated in this paper motivates an entirely new approach to the implementation of the Hamiltonian constraint in quantum gravity.
Early faint fault diagnosis of wheelset axlebox bearings in urban rail trains based on ICiSSA-MOMEDA
Authors: Yang Jianwei , Sun Runtao , Yao Dechen , Wang Jinhai , Li Xi , Hu Zhongshuo , Gao Cheng 
Published: October 2023

Abstract
Circulant Singular Spectrum Analysis (CiSSA) performs well in the decomposition and extraction of the periodic components of nonstationary signals. However, the decomposition of signals in complex environments suffers from spectral aliasing and difficulties in extracting feature information. Therefore, based on CiSSA, an improved CiSSA and multipoint optimal minimum entropy deconvolution adjustment (ICiSSA-MOMEDA) is proposed and applied to the early faint fault diagnosis of axlebox bearings of urban rail train wheelsets. First, the optimal embedding dimension was computed adaptively and accurately using an improved Cao’s method. Then, the initial components obtained from the decomposition were reorganized using the K-ARs method. ICiSSA effectively solves the problems of spectrum confusion and fault-information dispersion. Finally, ICiSSA was combined with MOMEDA to improve its ability to detect weak fault information. The superiority of ICiSSA-MOMEDA was verified based on the analysis of the actual bearing data and comparison with other methods.
Molecular dynamics simulation of the heterostructure of the CoCrFeMnNi high entropy alloy under an impact load
Authors: Chen Xiang , Liu Lei , Gao Rongjian , Lu Sheng , Fu Tao 
Published: October 2023

Abstract
There have been numerous experimental studies conducted on the CoCrFeMnNi high entropy alloys (HEAs) at the macroscopic level. However, it is challenging to quantitatively analyze the shock behavior of the HEAs from a microscopic level through experiments. In this study, we construct single-crystal, twin-crystal, multilayer, hole, and two-phase structures of the CoCrFeMnNi HEAs using the molecular dynamics method. The effects of impact loading on the microscopic level are investigated for CoCrFeMnNi HEAs with different structures. By analyzing the evolution of their microstructure and the changes in physical parameters, the response laws and propagation characteristics of shock waves in various heterogeneous of CoCrFeMnNi HEAs are revealed at the atomic scale.
Boosting learning achievement in physics among Ugandan form-2 students: effect of problem-based learning
Authors: Gumisirizah Nicholus , Muwonge Charles M , Nzabahimana Joseph 
Published: October 2023

Abstract
Enabling students to learn smoothly at an early stage of learning is a paramount effort that African education should takeoff. This study established the effect of problem-based learning (PBL) on students’ learning achievement. The participants were selected from form-2 of lower secondary schools in Sheema District, Western Uganda. Participants were randomly assigned to the treatment class with PBL instruction and the control class with content-based learning (CBL). A quantitative approach and a quasi-experimental design were used. Thus, the pretest-posttest non-equivalent quasi-experimental design was applied. A learning achievement test in simple machines was used as a data collection tool. The test was validated by experts and piloted with a split-half reliability (r = 0.87). Data was analysed in MS Excel and SPSS. A repeated measures analysis of variance revealed a very high statistically significant difference (p < .001) after learning in both classes. The same significance was found between PBL and CBL in favour of PBL. Classical test theory was used to present item difficulty and discrimination index. Teachers were recommended to adopt these methods with more practical hands-on activities to boost their skills and conceptual understanding.
Einsteinian gravitational concepts throughout secondary school
Authors: McInerney Corey , Sutton Phil 
Published: October 2023

Abstract
Einstein’s theory of relativity is largely thought of as one of the most important discoveries of the 20th century and continues to pass observational tests over 100 years later. Yet, it is Newtonian gravity, a 350 year old formalism proven to be less accurate than relativity, which is taught in schools. It has been shown that Einsteinian gravitational concepts can be well understood by students in both primary and secondary education. In this paper, a cross-section of students from Yr 7 to 13 enrolled in an English secondary school took part in an intervention designed to introduce the idea of gravity from spacetime curvature. The overall aim of this work is to assess the viability of including relativity in the secondary curriculum and to ascertain which year this material would be best placed in. We determine that all year groups where able to appreciate the effects of curvature to some extent. Visual demonstrations aided conceptual understanding at Yr 7–8 level, but this does not have a strong effect on their ideas around the source of the gravitational force. Participants in Yr 9–13 were able to understand concepts beyond those introduced in the demonstrations. However, a deeper understanding of curvature as the source of the gravitational force is not seen until years 12 and 13. We find that those in Yr 13 have the best overall understanding of the concepts introduced during our intervention.
Streamer-to-filament transition in pulsed nanosecond atmospheric pressure discharge: 2D numerical modeling
Authors: Zhang Bin , Zhu Yifei , Zhang Xiaobing , Popov Nikolay , Orriere Thomas , Pai David Z , Starikovskaia Svetlana M 
Published: October 2023

Abstract
The streamer-to-filament transition in air at atmospheric pressure, in a nanosecond pin-to-pin discharge, is studied by a 2D model. The main aim is to implement a kinetic scheme providing a sharp electron density increase to the 2D PASSKEy code, to validate the results on the available experimental data, and to investigate the mechanisms responsible for the transition. Results show that after the formation of a conductive channel across the discharge gap, two discharge modes appear during a few nanoseconds: a glow phase, with a relatively homogeneous distribution with the electron density of

1.0
×

10

14

cm−3, and a filamentary phase, with the electron density of

1.0
×

10

18

cm−3. Two filaments appear at the cathode and anode respectively, and propagate towards the middle of the gap with a velocity of about

1.1
⋅

10
7

cm s−1, forming a narrow channel. Simultaneously, the gas temperature increases from 350 to 2800 K. The diameter of the channel at the middle gap decreases from 210 to 90 µm. Dissociation and ionization of the electronically excited states of molecules N2(A

3

∑

u

+

, B

3

Π
g

, a

′
1

∑

u

−

, C

3

Π
u

), and ionization of ground and electronically excited states of O and N atoms are the most important processes for the transition. Numerical results also reveal the influence of the memory effect (pre-heating, pre-ionization, and pre-dissociation) from previous pulses on the streamer-to-filament transition.
Universal correlations along the BEC-BCS crossover
Authors: Obeso-Jureidini J C , Domínguez-Castro G A , Neri E , Paredes R , Romero-Rochín V 
Published: October 2023

Abstract
Universality of the long-distance behavior across the Bardeen–Cooper–Schrieffer (BEC)-Bose–Einstein condensate (BCS) smooth transition for two-body density correlation functions and the Cooper-pair probability density is demonstrated in a balanced mixture of a two-component Fermi gas at T = 0. It is numerically shown at the mean-field level that these two-body quantities exhibit an exponential decay in terms of the chemical potential and the low-energy behavior of the gap. A general expression is found for the two-body distributions holding for different features of finite-range potentials, such as divergences at the origin, discontinuities at a finite radius, power-law decay, and exponential decay. The correlation length characterizing the long-distance behavior unravels the dependence on the energy needed to break pairs along the BEC-BCS crossover, a quantity meaningful to the stability of the many-body state.
Anomalous luminescence temperature dependence of (In,Ga)(As,Sb)/GaAs/GaP quantum dots overgrown by a thin GaSb capping layer for nanomemory applications
Authors: Sala Elisa Maddalena , Klenovský Petr 
Published: October 2023

Abstract
We study (In,Ga)(As,Sb)/GaAs quantum dots (QDs) embedded in a GaP (100) matrix, which are overgrown by a thin GaSb capping layer with variable thickness. QD samples are studied by temperature-dependent photoluminescence, and we observe that the QD emission shows anomalous temperature dependence, i.e. increase of energy with temperature increase from 10 K to ∼70 K, followed by energy decrease for larger temperatures. With the help of fitting of luminescence spectra by Gaussian bands with energies extracted from eight band

k

⋅

p

theory with multiparticle corrections calculated using the configuration interaction method, we explain the anomalous temperature dependence as mixing of momentum direct and indirect exciton states. We also find that the k-indirect electron–hole transition in type-I regime at temperatures

<

70

K is optically more intense than k-direct. Furthermore, we identify a band alignment change from type-I to type-II for QDs overgrown by more than one monolayer of GaSb. Finally, we predict the retention time of (In,Ga)(As,Sb)/GaAs/AlP/GaP QDs capped with GaSb layers with varying thickness, for usage as storage units in the QD-Flash nanomemory concept and observe that by using only a 2 ML-thick GaSb capping layer, the projected storage time surpasses the non-volatility limit of ten years.