bluuebunny/crossref_metadata_2025 huggingface dataset:
Not exclusively the activity, but the sweet spot: a dehydrogenase point mutation synergistically boosts activity, substrate tolerance, thermal stability and yield
Authors: Cen Yu-Ke , Zhang Lin , Jiang Yue , Meng Xiang-Fu , Li Yuan , Xiang Chao , Xue Ya-Ping , Zheng Yu-Guo
Published: March 2024

A single-point mutation of 7α-HSDH achieved the highest activity and synergistically improved substrate tolerance, thermal stability, cofactor affinity, and conversion rate.
Mutasynthesis generates nine new pyrroindomycins
Authors: Wu Zhuhua , Xia Zhengxiang , Tang Zhijun , Li Ji'an , Liu Wen
Published: March 2024

Nine new pyrroindomycins with diverse acyl modification on their deoxy-trisaccharide moieties were created via a mutasynthesis approach. The key feature lies in blocking DHPI formation by gene pyrK1 inactivation and supplying chemical acyl precursors.
Correction: In situ construction of a continuous ionic conductive coating for a high-performance Li3VO4 anode
Authors: Wang Lulu , Zeng Cheng , Liang Jianing , Zhai Chun , Liu Hao , Zhai Tianyou , Li Huiqiao
Published: March 2024

Correction for ‘In situ construction of a continuous ionic conductive coating for a high-performance Li3VO4 anode’ by Lulu Wang et al., Inorg. Chem. Front., 2024, 11, 1177–1185, https://doi.org/10.1039/D3QI02235H.
Crystal structure, Hirshfeld surface analysis, conduction mechanism and electrical modulus study of the new organic–inorganic compound [C8H10NO]2HgBr4
Authors: Chkoundali Souad , Garoui Iheb , Trigui Wala , Oueslati Abderrazek
Published: March 2024

There has been a lot of interest in the development of a novel hybrid material based on mercury that has fascinating structural properties.
The role of solution temperature in characteristics of TiO2 nanotube arrays prepared on Ti foil in acid solution
Authors: Xian Wenhao , Liu Yingjie , Qi Qingjie , Liu Han , Wang Yue , Chen Changbin
Published: March 2024

The barrier layer thickness of the TNTs decrease with the solution temperature rises from −10 °C to 90 °C; the pulse temperature has an evident effect on the characteristics of TNTs in the case of two fixed temperatures.
Facile preparation of high-efficiency peroxidase mimics: modulation of the catalytic microenvironment of LDH nanozymes through defect engineering induced by amino acid intercalation
Authors: Han Dong , Yang Kui , Chen Lanlan , Zhang Zhaosheng , Wang Chen , Yan Hongyuan , Wen Jia
Published: March 2024

Twenty kinds of amino acids were separately intercalated into CoFe-LDH to regulate its catalytic microenvironment through defect engineering, thereby to screen out high-efficiency peroxidase mimics for biosensing and antibacterial applications.
Benchmarking pH-field coupled microkinetic modeling against oxygen reduction in large-scale Fe–azaphthalocyanine catalysts
Authors: Zhang Di , Hirai Yutaro , Nakamura Koki , Ito Koju , Matsuo Yasutaka , Ishibashi Kosuke , Hashimoto Yusuke , Yabu Hiroshi , Li Hao
Published: March 2024

Molecular Fe azaphthalocyanine catalysts with diverse long-chain “dancing patterns” demonstrate variable oxygen reduction reaction performance for fuel cells, aligning well with our pH-field coupled microkinetic model.
Axonal tension contributes to consistent fold placement
Authors: Wang Xincheng , Wang Shuolun , Holland Maria A.
Published: March 2024

We propose a novel bilayer finite element model incorporating axonal tension in the subcortex. Our results reveal that axonal tension serves as a perturbation that triggers folding and determines the placement of folds.
Tailored sulfonated carbons: unraveling enhanced catalytic dynamics for fructose dehydration under conventional and microwave heating
Authors: Reis Gabrielle Mathias , Machado Letícia Ferreira Lima , Nunes Renan Silva , Mandelli Dalmo , Carvalho Wagner Alves
Published: March 2024

Cooperation among active sites within a strongly acidic carbon allowed 80% conversion at 120 °C within a 5-minute reaction period.
Collaboratively improved energy density and efficiency in NaNbO3-based lead-free relaxor ferroelectrics via enhancing antiferrodistortion
Authors: Xie Aiwen , Lei Junwei , Zhang Yi , Rahman Attaur , Jiang Xuewen , Li Tianyu , Xie Xinchun , Liu Liqiang , Zhou Cong , Yin Shuang , Ma Haiqiang , Fang Xia , Zuo Ruzhong
Published: March 2024

A novel strategy for enhancing antiferrodistortion is proposed to effectively achieve simultaneously high energy density and efficiency in lead-free relaxor ferroelectric capacitors.
PEO-Li21Si5 as a pre-lithiation and structural protection layer for lithium-ion batteries
Authors: Zhang Zhiyong , Sun Zhefei , Pei Shanpeng , Liu Yan , Luo Linshan , Guo Shengshi , Han Xiang , Zhang Ziqi , Wang Fuming , Chen Songyan
Published: March 2024

Polyethylene oxide (PEO) was added to Li21Si5 to create a PEO-Li21Si5 pre-lithiation layer, which was coated on the surface of the Si@C anode. This strategy achieved an initial coulombic efficiency (ICE) of over 100% with stable and long-lasting cycles.
Understanding phase evolution of ferroelectric Hf0.5Zr0.5O2 thin films with Al2O3 and Y2O3 inserted layers
Authors: Shin Jonghoon , Seo Haengha , Ye Kun Hee , Jang Yoon Ho , Kwon Dae Seon , Lim Junil , Kim Tae Kyun , Paik Heewon , Song Haewon , Kim Ha Ni , Byun Seungyong , Shin Seong Jae , Kim Kyung Do , Lee Yong Bin , Lee In Soo , Choi Jung-Hae , Hwang Cheol Seong
Published: March 2024

This study investigates the insertion traits of the Al2O3 and Y2O3 insertion layers (ILs) and their effects on the phase evolution and electrical characteristics of polycrystalline Hf0.5Zr0.5O2 (HZO) thin films grown by atomic layer deposition (ALD).
The Validity and Reliability of the Turkish Version of Preschool Hearing Environments and Reflection on Quality of Life Questionnaire
Authors: Kırseven Sinem , Tahir Emel , Yaşar Özlem Cangökçe
Published: March 2024

Purpose:

The purpose of this study was to assess preschool children's hearing-related quality of life and to introduce the scale, originally titled “Preschool Hearing Environments and Reflections on Quality of Life Questionnaire” (Preschool HEAR-QL), to the literature through Turkish adaption, validity, and reliability analyses.

Method:

Our study included 210 children aged 2–6 years: 110 with hearing loss (56 cochlear implant users and 54 hearing aid users) and 100 with normal hearing. Demographic data were collected and then the Preschool HEAR-QL, which was translated into Turkish, was administered twice at 15-day intervals. Confirmatory factor analysis was used to determine whether the factor structure found in the original scale development study was confirmed in our sample (construct validity). Cronbach's alpha, intraclass correlation scores, and the test–retest method were used to assess the scale's reliability as the findings were analyzed using paired samples
t
tests.

Results:

The children with hearing loss had lower scores than their normal-hearing peers, and the difference was significant in the subdomains of behavior and attention, hearing environments, and communication. The subscale of the Preschool Period Listening Environments and their Reflections on Quality of Life Scale consists of 23 items, and Cronbach's alpha value was found as 0.922 in the first application and 0.926 in the second application (high reliability). In the model established for validity analysis, χ
2
/
df
= 2.156, root-mean-square error of approximation = 0.074, standard root-mean-square residual = 0.078, goodness-of-fit index = 0.830, adjusted goodness-of-fit index = 0.789, comparative fit index = 0.895, and Tucker–Lewis index = 0.881 (good model fit). In terms of test–retest reliability, the correlation between the two measurements was 0.837, and there was no statistical difference between the test–retest scores (
p
= .15).

Conclusion:

The Turkish version of the Preschool HEAR-QL scale was proven to be a valid and reliable scale for assessing the hearing-related quality of life of children aged 2–6 years.

Supplemental Material:

https://doi.org/10.23641/asha.25236949
A case study on the barriers towards achieving sustainable smart city for Abu Dhabi
Authors: Ajaj Rahaf , Buniya Mohanad Kamil , Wuni Ibrahim Yahaya , Yousif Omar Sedeeq
Published: March 2024

Developing sustainable smart cities (SSCs) is crucial to modern urban growth, as recognised in various international policies and literature. With Abu Dhabi as a focus, this research aims to identify and evaluate the primary obstacles that hinder the creation of intelligent and sustainable cities. By categorising and ranking these barriers, the study seeks to prioritise the most significant hindrances to smart city development. The research analysed 31 barriers, classified them into six groups, and examined them through existing literature. Semi‐structured interviews with stakeholders responsible for implementing the SSC strategy provided additional valuable insights. The study used the Partial Least Squares Path Modelling method to prioritise the selected barriers. The results showed that the most significant barriers to SSC development were in the Economic category, followed by Technology, Governance, Social, Legal, Ethical, and Environmental barriers. This research provides valuable insights for policymakers and the Abu Dhabi government to eliminate obstacles that hinder SSC development initiatives.
Self-supervised component separation for the extragalactic submillimetre sky
Authors: Bonjean V. , Tanimura H. , Aghanim N. , Bonnaire T. , Douspis M.
Published: March 2024

We use a new approach based on self-supervised deep learning networks originally applied to transparency separation in order to simultaneously extract the components of the extragalactic submillimeter sky, namely the cosmic microwave background (CMB), the cosmic infrared background (CIB), and the Sunyaev–Zeldovich (SZ) effect. In this proof-of-concept paper, we test our approach on the WebSky extragalactic simulation maps in a range of frequencies from 93 to 545 GHz, and compare with one of the state-of-the-art traditional methods, MILCA, for the case of SZ. We first visually compare the images, and then statistically analyse the full-sky reconstructed high-resolution maps with power spectra. We study the contamination from other components with cross spectra, and particularly emphasise the correlation between the CIB and the SZ effect and compute SZ fluxes around positions of galaxy clusters. The independent networks learn how to reconstruct the different components with less contamination than MILCA. Although this is tested here in an ideal case (without noise, beams, or foregrounds), this method shows significant potential for application in future experiments such as the Simons Observatory (SO) in combination with the Planck satellite.
The Simons Observatory: Pipeline comparison and validation for large-scale B-modes
Authors: Wolz Kevin , Azzoni Susanna , Hervías-Caimapo Carlos , Errard Josquin , Krachmalnicoff Nicoletta , Alonso David , Baccigalupi Carlo , Baleato Lizancos Antón , Brown Michael L. , Calabrese Erminia , Chluba Jens , Dunkley Jo , Fabbian Giulio , Galitzki Nicholas , Jost Baptiste , Morshed Magdy , Nati Federico
Published: March 2024

Context. The upcoming Simons Observatory Small Aperture Telescopes aim at achieving a constraint on the primordial tensor-to-scalar ratio r at the level of σ(r = 0)≲0.003, observing the polarized CMB in the presence of partial sky coverage, cosmic variance, inhomogeneous non-white noise, and Galactic foregrounds.

Aims. We present three different analysis pipelines able to constrain r given the latest available instrument performance, and compare their predictions on a set of sky simulations that allow us to explore a number of Galactic foreground models and elements of instrumental noise, relevant for the Simons Observatory.

Methods. The three pipelines employ different combinations of parametric and non-parametric component separation at the map and power spectrum levels, and use B-mode purification to estimate the CMB B-mode power spectrum. We applied them to a common set of simulated realistic frequency maps, and compared and validated them with focus on their ability to extract robust constraints on the tensor-to-scalar ratio r. We evaluated their performance in terms of bias and statistical uncertainty on this parameter.

Results. In most of the scenarios the three methodologies achieve similar performance. Nevertheless, several simulations with complex foreground signals lead to a > 2σ bias on r if analyzed with the default versions of these pipelines, highlighting the need for more sophisticated pipeline components that marginalize over foreground residuals. We show two such extensions, using power-spectrum-based and map-based methods, that are able to fully reduce the bias on r below the statistical uncertainties in all foreground models explored, at a moderate cost in terms of σ(r).
Characterizing B stars from Kepler/K2 Campaign 11
Authors: Pereira Alan W. , Janot-Pacheco Eduardo , Emilio Marcelo , Andrade Laerte , Armstrong James D. , Eidam Jéssica M. , Rabello-Soares M. Cristina , da Silva Bergerson V. H. V.
Published: March 2024

Aims. In this study, we analyze 122 B-type star candidates observed during Campaign 11 of the Kepler/K2 mission to investigate their variability and pulsation characteristics. A subset of 45 B star candidates was observed during the Kepler/K2 mission’s Campaign 11 between September and December 2016. Our analyses aim to gain a deeper understanding of the physical characteristics of these massive stars. Our methods involve both spectroscopy and seismology. The spectroscopic analysis was performed through mediumresolution blue spectra, which also allowed us to perform a spectral classification of the objects. Our results will contribute to the ongoing effort to expand our knowledge of variable B stars and the processes that drive their variability.

Methods. We used the iterative prewhitening and wavelet frequency searching algorithms to analyze the light curves to identify the different types of variability in the data. The frequencies were carefully chosen based on the signal-to-noise ratio and the magnitude of errors. We applied spectroscopic analysis techniques to enhance our understanding of the observed stars, including SME and MESA algorithms. A spectral classification was performed based on the observed spectra. The resulting astrophysical parameters were compared to Gaia mission data. Additionally, a seismology technique was applied to determine the average internal rotation frequency (vrot) and buoyancy travel time (P0) for selected stars in the sample.

Results. We detected several types of variability among the B-type stars, including slowly pulsating B (SPB) stars, hybrid pulsators showing both β Cep and SPB pulsations, stars with stochastic low-frequency (SLF) variability, Maia variables, and SPB/Maia hybrids. Their positions in our Gaia and classical HR diagrams are compatible with the theoretical expectations. We also found stars exhibiting variability attributed to binarity and rotation. We determined the physical characteristics for 45 of our targets and conducted a seismic analysis for 14 objects. Two SPB/Maia stars show internal velocities comparable to those of fast SPB stars. The derived average rotation frequencies, vrot, for these 14 stars lie between the critical vcritRoche and the minimal frequency values of vlimrot implied by the υ sin i measured from the spectra.

Conclusions. Our analysis classified 41 stars as SPB stars and attributed the primary variability of 53 objects to binarity, rotation, or both. We identified five stars as Maia/fast-rotating SPB variables. Two stars were classified as hybrid SPB/β Cep pulsators, and one as a β Cep binary. Thirteen stars exhibited prominent, low-frequency power excess, indicating SLF variability. Additionally, we found a positive correlation between the dominant fg frequency and the internal average rotation frequency.
ALMA-IMF
Authors: Armante M. , Gusdorf A. , Louvet F. , Motte F. , Pouteau Y. , Lesaffre P. , Galván-Madrid R. , Dell’Ova P. , Bonfand M. , Nony T. , Brouillet N. , Cunningham N. , Ginsburg A. , Men’shchikov A. , Bontemps S. , Díaz-González D. , Csengeri T. , Fernández-López M. , González M. , Herpin F. , Liu H.-L. , Sanhueza P. , Stutz A.M. , Valeille-Manet M.
Published: March 2024

Context. One of the central questions in astrophysics is the origin of the initial mass function (IMF). It is intrinsically linked to the processes from which it originates, and hence its connection with the core mass function (CMF) must be elucidated.

Aims. We aim to measure the CMF in the evolved W33-Main star-forming protocluster to compare it with CMF recently obtained in other Galactic star-forming regions, including the ones that are part of the ALMA-IMF program.

Methods. We used observations from the ALMA-IMF large programme: ~2′ × 2′ maps of emission from the continuum and selected lines at 1.3 mm and 3 mm observed by the ALMA 12m only antennas. Our angular resolution was typically 1″, that is, ~2400 au at a distance of 2.4 kpc. The lines we analysed are CO (2–1), SiO (5–4), N2H+ (1–0), H41α as well as He41α blended with C41α. We built a census of dense cores in the region, and we measured the associated CMF based on a core-dependent temperature value.

Results. We confirmed the ‘evolved’ status of W33-Main by identifiying three H II regions within the field, and to a lesser extent based on the number and extension of N2H+ filaments. We produced a filtered core catalogue of 94 candidates that we refined to take into account the contamination of the continuum by free-free and line emission, obtaining 80 cores with masses that range from 0.03 to 13.2 M⊙. We fitted the resulting high-mass end of the CMF with a single power law of the form N(log(M)) ∝ Mα, obtaining α = −1.44−0.22+0.16, which is slightly steeper but consistent with the Salpeter index. We categorised our cores as prestellar and protostellar, mostly based on outflow activity and hot core nature. We found the prestellar CMF to be steeper than a Salpeter-like distribution, and the protostellar CMF to be slightly top heavy. We found a higher proportion of cores within the H II regions and their surroundings than in the rest of the field. We also found that the cores’ masses were rather low (maximum mass of ~13 M⊙).

Conclusions. We find that star formation in W33-Main could be compatible with a ‘clump-fed’ scenario of star formation in an evolved cloud characterised by stellar feedback in the form of H II regions, and under the influence of massive stars outside the field. Our results differ from those found in less evolved young star-forming regions in the ALMA-IMF program. Further investigations are needed to elucidate the evolution of late CMFs towards the IMF over statistically significant samples.
A deep search for large complex organic species toward IRAS16293-2422 B at 3 mm with ALMA
Authors: Nazari P. , Cheung J. S. Y. , Asensio J. Ferrer , Murillo N. M. , van Dishoeck E. F. , Jørgensen J. K. , Bourke T. L. , Chuang K.-J. , Drozdovskaya M. N. , Fedoseev G. , Garrod R. T. , Ioppolo S. , Linnartz H. , McGuire B. A. , Müller H. S. P. , Qasim D. , Wampfler S. F.
Published: March 2024

Context. Complex organic molecules (COMs) have been detected ubiquitously in protostellar systems. However, at shorter wavelengths (~0.8 mm), it is generally more difficult to detect larger molecules than at longer wavelengths (~3 mm) because of the increase in millimeter dust opacity, line confusion, and unfavorable partition function.

Aims. We aim to search for large molecules (more than eight atoms) in the Atacama Large Millimeter/submillimeter Array (ALMA) Band 3 spectrum of IRAS 16293-2422 B. In particular, the goal is to quantify the usability of ALMA Band 3 for molecular line surveys in comparison to similar studies at shorter wavelengths.

Methods. We used deep ALMA Band 3 observations of IRAS 16293-2422 B to search for more than 70 molecules and identified as many lines as possible in the spectrum. The spectral settings were set to specifically target three-carbon species such as i- and n-propanol and glycerol, the next step after glycolaldehyde and ethylene glycol in the hydrogenation of CO. We then derived the column densities and excitation temperatures of the detected species and compared the ratios with respect to methanol between Band 3 (~3 mm) and Band 7 (~1 mm, Protostellar Interferometric Line Survey) observations of this source to examine the effect of the dust optical depth.

Results. We identified lines of 31 molecules including many oxygen-bearing COMs such as CH3OH, CH2OHCHO, CH3CH2OH, and c-C2H4O and a few nitrogen- and sulfur-bearing ones such as HOCH2CN and CH3SH. The largest detected molecules are gGg-(CH2OH)2 and CH3COCH3. We did not detect glycerol or i- and n-propanol, but we do provide upper limits for them which are in line with previous laboratory and observational studies. The line density in Band 3 is only ~2.5 times lower in frequency space than in Band 7. From the detected lines in Band 3 at a ≳ 6σ level, ~25–30% of them could not be identified indicating the need for more laboratory data of rotational spectra. We find similar column densities and column density ratios of COMs (within a factor ~2) between Band 3 and Band 7.

Conclusions. The effect of the dust optical depth for IRAS 16293-2422 B at an off-source location on column densities and column density ratios is minimal. Moreover, for warm protostars, long wavelength spectra (~3 mm) are not only crowded and complex, but they also take significantly longer integration times than shorter wavelength observations (~0.8 mm) to reach the same sensitivity limit. The 3 mm search has not yet resulted in the detection of larger and more complex molecules in warm sources. A full deep ALMA Band 2–3 (i.e., ~3–4 mm wavelengths) survey is needed to assess whether low frequency data have the potential to reveal more complex molecules in warm sources.
First evidence of a connection between cluster-scale diffuse radio emission in cool-core galaxy clusters and sloshing features
Authors: Biava N. , Bonafede A. , Gastaldello F. , Botteon A. , Brienza M. , Shimwell T. W. , Brunetti G. , Bruno L. , Rajpurohit K. , Riseley C. J. , van Weeren R. J. , Rossetti M. , Cassano R. , De Gasperin F. , Drabent A. , Rottgering H. J. A. , Edge A. C. , Tasse C.
Published: March 2024

Context. Radio observations of a few cool-core galaxy clusters have revealed the presence of diffuse emission on cluster scales, similar to what was found in merging clusters in the form of radio halos. These sources might suggest that a minor merger, while not sufficiently energetic to disrupt the cool core, could still trigger particle acceleration in the intracluster medium on scales of hundreds of kiloparsecs.

Aims. We aim to verify the occurrence of cluster-scale diffuse radio emission in cool-core clusters and test the minor merger scenario.

Methods. With the LOw Frequency ARray (LOFAR) at 144 MHz, we observed a sample of twelve cool-core galaxy clusters presenting some level of dynamical disturbances, according to X-ray data. We also performed a systematic search of cold fronts in these clusters, re-analysing archival Chandra observations.

Results. The clusters PSZ1G139.61+24, A1068 (new detection), MS 1455.0+2232, and RX J1720.1+2638 present diffuse radio emission on a cluster scale (r ≥ 0.2R500). This emission is characterised by a double component: a central mini-halo confined by cold fronts and diffuse emission on larger scales, whose radio power at 144 MHz is comparable to that of radio halos detected in merging systems with the same cluster mass. The cold fronts in A1068 are a new detection. We also found a candidate plasma depletion layer in this cluster. No sloshing features are found in the other eight clusters. Two of them present a mini-halo, with diffuse radio emission confined to the cluster core. We also found a new candidate mini-halo. Whereas, for the remaining five clusters, we did not detect halo-like emission. For clusters without cluster-scale halos, we derived upper limits to the radio halo power.

Conclusions. We found that cluster-scale diffuse radio emission is not present in all cool-core clusters when observed at a low frequency, but it is correlated to the presence of cold fronts. The coexistence of cluster-scale diffuse radio emission and cold fronts in cool-core clusters requires a specific configuration of the merger and so it puts some constraints on the turbulence, which deserves to be investigated in the future with theoretical works.
Search for radio halos in starburst galaxies
Authors: Galante C. A. , Saponara J. , Romero G. E. , Benaglia P.
Published: March 2024

Context. Starburst galaxies are undergoing intense episodes of star formation. In these galaxies, gas is ejected into the surrounding environment through winds created by the effect of hot stars and supernova explosions. When interacting with the intergalactic medium, these winds can produce strong shocks capable of accelerating cosmic rays. The radiation from these cosmic rays mainly occurs in radio and gamma rays. The radio halo can be characterized using the scale height, which is an important parameter for understanding cosmic ray acceleration and transport.

Aims. We searched for the presence of radio halos in a sample of edge-on starburst galaxies gathered from the MeerKAT 1.28 GHz Atlas of Southern Sources in the IRAS Revised Bright Galaxy Sample. The investigation of how the radio halos relate to the global properties of the galaxies can shed light on the understanding of the halo origin and the underlying cosmic ray population.

Methods. We selected a sample of 25 galaxies with inclinations i > 80° from the original sample and modeled their disk and halo contributions. We determined the scale heights and the radio luminosity of the halos when detected.

Results. We have detected and characterized 11 radio halos from a sample of 25 edge-on galaxies. Seven of them are reported here for the first time. The average radio scale height is ∼1 kpc. We found that the halo scale heights increase linearly with the radio diameters and this relation does not depend on the star formation rate. All galaxies in our sample follow the radio-infrared relation with a q parameter value of 2.5 ± 0.1. The halo luminosity linearly increases with the infrared luminosity and star formation rate.

Conclusions. The dependence of the halo luminosity on the star formation rate and the infrared luminosity supports the hypothesis that the radio halos are the result of synchrotron radiation produced by relativistic electrons and points toward the fact that the star formation activity plays a crucial role in halo creation. The average scale height of 1 kpc implies a dynamical range of 4 Myr, several orders of magnitude greater than the synchrotron losses for electrons of 10 TeV. This suggests that some process must exist to reaccelerate cosmic rays in the halo if gamma-ray emission of a leptonic origin is detected from the halo. According to the relation between the radio and gamma-ray luminosities, we found that NGC 4666 is a potential gamma-ray source for future observations.
First detection of the [CII] 158 µm line in the intermediate-velocity cloud Draco
Authors: Schneider Nicola , Ossenkopf-Okada Volker , Keilmann Eduard , Röllig Markus , Kabanovic Slawa , Bonne Lars , Csengeri Timea , Klein Bernd , Simon Robert , Comerón Fernando
Published: March 2024

High-latitude intermediate-velocity clouds (IVCs) are part of the Milky Way’s H I halo and originate from either a galactic fountain process or extragalactic gas infall. They are partly molecular and can most of the time be identified in CO. Some of these regions also exhibit high-velocity cloud gas, which is mostly atomic, and gas at local velocities (LVCs), which is partly atomic and partly molecular. We conducted a study on the IVCs Draco and Spider, both were exposed to a very weak UV field, using the spectroscopic receiver upGREAT on the Stratospheric Observatory for Infrared Astronomy (SOFIA). The 158 µm fine-structure line of ionized carbon ([C II]) was observed, and the results are as follows: In Draco, the [C II] line was detected at intermediate velocities (but not at local or high velocities) in four out of five positions. No [C II] emission was found at any velocity in the two observed positions in Spider. To understand the excitation conditions of the gas in Draco, we analyzed complementary CO and H I data as well as dust column density and temperature maps from Herschel. The observed [C II] intensities suggest the presence of shocks in Draco that heat the gas and subsequently emit in the [C II] cooling line. These shocks are likely caused by the fast cloud’s motion toward the Galactic plane that is accompanied by collisions between H I clouds. The nondetection of [C II] in the Spider IVC and LVC as well as in other low-density clouds at local velocities that we present in this paper (Polaris and Musca) supports the idea that highly dynamic processes are necessary for [C II] excitation in UV-faint low-density regions.
CHEX-MATE: Robust reconstruction of temperature profiles in galaxy clusters with XMM-Newton
Authors: Rossetti M. , Eckert D. , Gastaldello F. , Rasia E. , Pratt G. W. , Ettori S. , Molendi S. , Arnaud M. , Balboni M. , Bartalucci I. , Batalha R. M. , Borgani S. , Bourdin H. , De Grandi S. , De Luca F. , De Petris M. , Forman W. , Gaspari M. , Ghizzardi S. , Iqbal A. , Kay S. , Lovisari L. , Maughan B. J. , Mazzotta P. , Pointecouteau E. , Riva G. , Sayers J. , Sereno M.
Published: March 2024

The “Cluster HEritage project with XMM-Newton: Mass Assembly and Thermodynamics at the End point of structure formation” (CHEX-MATE) is a multi-year heritage program to obtain homogeneous XMM-Newton observations of a representative sample of 118 galaxy clusters. The observations are tuned to reconstruct the distribution of the main thermodynamic quantities of the intra-cluster medium up to R500 and to obtain individual mass measurements, via the hydrostatic-equilibrium equation, with a precision of 15−20%. Temperature profiles are a necessary ingredient for the scientific goals of the project and it is thus crucial to derive the best possible temperature measurements from our data. This is why we have built a new pipeline for spectral extraction and analysis of XMM-Newton data, based on a new physically motivated background model and on a Bayesian approach with Markov chain Monte Carlo methods, which we present in this paper for the first time. We applied this new method to a subset of 30 galaxy clusters representative of the CHEX-MATE sample and show that we can obtain reliable temperature measurements up to regions where the source intensity is as low as 20% of the background, keeping systematic errors below 10%. We compare the median profile of our sample and the best-fit slope at large radii with literature results and we find a good agreement with other measurements based on XMM-Newton data. Conversely, when we exclude the most contaminated regions, where the source intensity is below 20% of the background, we find significantly flatter profiles, in agreement with predictions from numerical simulations and independent measurements with a combination of Sunyaev–Zeldovich and X-ray imaging data.
A 3D picture of moist-convection inhibition in hydrogen-rich atmospheres: Implications for K2-18 b
Authors: Leconte Jérémy , Spiga Aymeric , Clément Noé , Guerlet Sandrine , Selsis Franck , Milcareck Gwenaël , Cavalié Thibault , Moreno Raphaël , Lellouch Emmanuel , Carrión-González Óscar , Charnay Benjamin , Lefèvre Maxence
Published: March 2024

While small Neptune-like planets are among the most abundant exoplanets, our understanding of their atmospheric structure and dynamics remains sparse. In particular, many unknowns remain regarding the way moist convection works in these atmospheres, where condensable species are heavier than the non-condensable background gas. While it has been predicted that moist convection could cease above some threshold abundance of these condensable species, this prediction is based on simple linear analysis and relies on some strong assumptions regarding the saturation of the atmosphere. To investigate this issue, we developed a 3D cloud-resolving model for hydrogen-dominated atmospheres with large amounts of condensable species and applied it to a prototypical temperate Neptune-like planet – K2-18 b. Our model confirms the inhibition of moist convection above a critical abundance of condensable vapor and the onset of a stably stratified layer in the atmosphere of such planets, which leads to much hotter deep atmospheres and interiors. Our 3D simulations further provide quantitative estimates of the turbulent mixing in this stable layer, which is a key driver of the cycling of condensables in the atmosphere. This allowed us to build a very simple, yet realistic, 1D model that captures the most salient features of the structure of Neptune-like atmospheres. Our qualitative findings on the behavior of moist convection in hydrogen atmospheres go beyond temperate planets and should also apply to regions where iron and silicates condense in the deep interior of hydrogen-dominated planets. Finally, we used our model to investigate the likelihood of a liquid ocean beneath an H2-dominated atmosphere on K2-18 b. We find that the planet would need to have a very high albedo (A > 0.5–0.6) to sustain a liquid ocean. However, due to the spectral type of the star, the amount of aerosol scattering that would be needed to provide such a high albedo is inconsistent with the latest observational data.
Evolution of a stellar system in the context of the virial equation
Authors: Terebizh Valery Yu.
Published: March 2024

The virial equation is used to clarify the nature of the dynamic evolution of a stellar system. The methods used are based on analytical and numerical modeling of evolution, as well as on an approach long used in the nonlinear theory of oscillations. It is shown that the mean harmonic radius of a system with negative total energy never exceeds two times the equilibrium value. The time to reach the virial equlibrium state Tv is about two to three dozen dynamic time periods Td. For systems not in close proximity to virial equilibrium, the virial ratio, the mean harmonic radius, and the root mean square radius of the system fluctuate during Tv; then the virial ratio and mean harmonic radius stabilize near their equilibrium values, while the root mean square radius continues to increase (possibly ad infinitum). Thus, the moment of inertia of the system relative to the center of gravity and its potential energy have significantly different behavior, which leads to the formation of a relatively small quasi-equilibrium core and an extended halo.
Cloud properties across spatial scales in simulations of the interstellar medium
Authors: Colman Tine , Brucy Noé , Girichidis Philipp , Glover Simon C. O. , Benedettini Milena , Soler Juan D. , Tress Robin G. , Traficante Alessio , Hennebelle Patrick , Klessen Ralf S. , Molinari Sergio , Miville-Deschênes Marc-Antoine
Published: March 2024

Context. Molecular clouds (MCs) are structures of dense gas in the interstellar medium (ISM) that extend from ten to a few hundred parsecs and form the main gas reservoir available for star formation. Hydrodynamical simulations of a varying complexity are a promising way to investigate MCs evolution and their properties. However, each simulation typically has a limited range in resolution and different cloud extraction algorithms are used, which complicates the comparison between simulations.

Aims. In this work, we aim to extract clouds from different simulations covering a wide range of spatial scales. We compare their properties, such as size, shape, mass, internal velocity dispersion, and virial state.

Methods. We applied the HOP cloud detection algorithm on (M)HD numerical simulations of stratified ISM boxes and isolated galactic disk simulations that were produced using FLASH, RAMSES, and AREPO.

Results. We find that the extracted clouds are complex in shape, ranging from round objects to complex filamentary networks in all setups. Despite the wide range of scales, resolution, and sub-grid physics, we observe surprisingly robust trends in the investigated metrics. The mass spectrum matches in the overlap between simulations without rescaling and with a high-mass power-law index of −1 for logarithmic bins of mass, in accordance with theoretical predictions. The internal velocity dispersion scales with the size of the cloud as σ ∝ R0.75 for large clouds (R ≳ 3 pc). For small clouds we find larger σ compared to the power-law scaling, as seen in observations, which is due to supernova-driven turbulence. Almost all clouds are gravitationally unbound with the virial parameter scaling as αvir ∝ M−04, which is slightly flatter compared to observed scaling but in agreement given the large scatter. We note that the cloud distribution towards the low-mass end is only complete if the more dilute gas is also refined, rather than only the collapsing regions.
The GAPS Programme at TNG
Authors: Guilluy G. , D’Arpa M. C. , Bonomo A. S. , Spinelli R. , Biassoni F. , Fossati L. , Maggio A. , Giacobbe P. , Lanza A. F. , Sozzetti A. , Borsa F. , Rainer M. , Micela G. , Affer L. , Andreuzzi G. , Bignamini A. , Boschin W. , Carleo I. , Cecconi M. , Desidera S. , Fardella V. , Ghedina A. , Mantovan G. , Mancini L. , Nascimbeni V. , Knapic C. , Pedani M. , Petralia A. , Pino L. , Scandariato G. , Sicilia D. , Stangret M. , Zingales T.
Published: March 2024

Context. Atmospheric escape plays a fundamental role in shaping the properties of exoplanets. The metastable near-infrared (nIR) helium triplet at 1083.3 nm (HeI) is a powerful proxy of extended and evaporating atmospheres.

Aims. We used the GIARPS (GIANO-B + HARPS-N) observing mode of the Telescopio NazionaleGalileoto search for HeIabsorption in the upper atmospheres of five close-in giant planets hosted by the K and M dwarf stars of our sample, namely WASP-69 b, WASP-107 b, HAT-P-11 b, GJ 436 b, and GJ 3470 b.

Methods. We focused our analysis on the nIR HeItriplet, performing high-resolution transmission spectroscopy by comparing the in-transit and out-of-transit observations. In instances where nightly variability in the HeIabsorption signal was identified, we investigated the potential influence of stellar magnetic activity on the planetary absorption signal by searching for variations in the Hαtransmission spectrum.

Results. We spectrally resolve the HeItriplet and confirm the published detections for WASP-69 b (3.91 ± 0.22%, 17.6σ), WASP-107 b (8.17−0.76+0.80%, 10.5σ), HAT-P-11 b (1.36 ± 0.17%, 8.0σ), and GJ 3470 b (1.75−0.36+0.39%, 4.7σ). We do not find evidence of extra absorption for GJ 436 b. We observe night-to-night variations in the HeIabsorption signal for WASP-69 b, associated with variability in Hα, which likely indicates the influence of pseudo-signals related to stellar activity. Additionally, we find that the HeIsignal of GJ 3470 b originates from a single transit observation, thereby corroborating the discrepancies found in the existing literature. An inspection of the Hαline reveals an absorption signal during the same transit event.

Conclusions. By combining our findings with previous analyses of GIANO-B HeImeasurements of planets orbiting K dwarfs, we explore potential trends with planetary and stellar parameters that are thought to affect the absorption of metastable HeI. Our analysis is unable to identify clear patterns, thus emphasising the necessity for additional measurements and the exploration of potential additional parameters that may be important in controlling HeIabsorption in planetary upper atmospheres.
Cosmic evolution of black hole spin and galaxy orientations: Clues from the NewHorizon and Galactica simulations
Authors: Peirani Sébastien , Suto Yasushi , Beckmann Ricarda S. , Volonteri Marta , Lin Yen-Ting , Dubois Yohan , Yi Sukyoung K. , Pichon Christophe , Kraljic Katarina , Park Minjung , Devriendt Julien , Han San , Chen Wei-Huai
Published: March 2024

Black holes (BHs) are ubiquitous components of the center of most galaxies. In addition to their mass, the BH spin, through its amplitude and orientation, is a key factor in the galaxy formation process, as it controls the radiative efficiency of the accretion disk and relativistic jets. Using the recent cosmological high-resolution zoom-in simulations, NEWHORIZON and GALACTICA, in which the evolution of the BH spin is followed on the fly, we have tracked the cosmic history of a hundred BHs with a mass greater than 2 × 104 M⊙. For each of them, we have studied the variations of the three-dimensional angle (Ψ) subtended between the BH spins and the angular momentum vectors of their host galaxies (estimated from the stellar component). The analysis of the individual evolution of the most massive BHs suggests that they are generally passing by three different regimes. First, for a short period after their birth, low-mass BHs (MBH < 3 × 104 M⊙) are rapidly spun up by gas accretion and their spin tends to be aligned with their host galaxy spin. Then follows a second phase in which the accretion of gas onto low-mss BHs (MBH ≲ 105 M⊙) is quite chaotic and inefficient, reflecting the complex and disturbed morphologies of forming proto-galaxies at high redshifts. The variations of Ψ are rather erratic during this phase and are mainly driven by the rapid changes of the direction of the galaxy angular momentum. Then, in a third and long phase, BHs are generally well settled in the center of galaxies around which the gas accretion becomes much more coherent (MBH > 105 M⊙). In this case, the BH spins tend to be well aligned with the angular momentum of their host galaxy and this configuration is generally stable even though BH merger episodes can temporally induce misalignment. We even find a few cases of BH-galaxy spin anti-alignment that lasts for a long time in which the gas component is counter-rotating with respect to the stellar component. We have also derived the distributions of cos(Ψ) at different redshifts and found that BHs and galaxy spins are generally aligned. Our analysis suggests that the fraction of BH-galaxy pairs with low Ψ values reaches maximum at z ∼ 4 − 3, and then decreases until z ∼ 1.5 due to the high BH-merger rate. Afterward, it remains almost constant probably due to the fact that BH mergers becomes rare, except for a slight increase at late times. Finally, based on a Monte Carlo method, we also predict statistics for the 2D projected spin-orbit angles λ. In particular, the distribution of λ traces the alignment tendency well in the three-dimensional analysis. Such predictions provide an interesting background for future observational analyses.
Expanding the frontiers of cool-dwarf asteroseismology with ESPRESSO
Authors: Campante T. L. , Kjeldsen H. , Li Y. , Lund M. N. , Silva A. M. , Corsaro E. , Gomes da Silva J. , Martins J. H. C. , Adibekyan V. , Azevedo Silva T. , Bedding T. R. , Bossini D. , Buzasi D. L. , Chaplin W. J. , Costa R. R. , Cunha M. S. , Cristo E. , Faria J. P. , García R. A. , Huber D. , Lundkvist M. S. , Metcalfe T. S. , Monteiro M. J. P. F. G. , Neitzel A. W. , Nielsen M. B. , Poretti E. , Santos N. C. , Sousa S. G.
Published: March 2024

Fuelled by space photometry, asteroseismology is vastly benefitting the study of cool main-sequence stars, which exhibit convection-driven solar-like oscillations. Even so, the tiny oscillation amplitudes in K dwarfs continue to pose a challenge to space-based asteroseismology. A viable alternative is offered by the lower stellar noise over the oscillation timescales in Doppler observations. In this Letter we present the definite detection of solar-like oscillations in the bright K5 dwarf ϵ Indi based on time-intensive observations collected with the ESPRESSO spectrograph at the VLT, thus making it the coolest seismic dwarf ever observed. We measured the frequencies of a total of 19 modes of degree ℓ = 0–2 along with νmax = 5305 ± 176 μHz and Δν = 201.25 ± 0.16 μHz. The peak amplitude of radial modes is 2.6 ± 0.5 cm s−1, or a mere ∼14% of the solar value. Measured mode amplitudes are ∼2 times lower than predicted from a nominal L/M scaling relation and favour a scaling closer to (L/M)1.5 below ∼5500 K, carrying important implications for our understanding of the coupling efficiency between pulsations and near-surface convection in K dwarfs. This detection conclusively shows that precise asteroseismology of cool dwarfs is possible down to at least the mid-K regime using next-generation spectrographs on large-aperture telescopes, effectively opening up a new domain in observational asteroseismology.
Optimal Asymmetric Quantum Codes from the Euclidean Sums of Linear Codes
Authors: XU Peng , LIU Xiusheng
Published: March 2024

In this paper, we first give the definition of the Euclidean sums of linear codes, and prove that the Euclidean sums of linear codes are Euclidean dual-containing. Then we construct two new classes of optimal asymmetric quantum error-correcting codes based on Euclidean sums of the Reed-Solomon codes, and two new classes of optimal asymmetric quantum error-correcting codes based on Euclidean sums of linear codes generated by Vandermonde matrices over finite fields. Moreover, these optimal asymmetric quantum error-correcting codes constructed in this paper are different from the ones in the literature.
Learning Label Correlations for Multi-Label Online Passive Aggressive Classification Algorithm
Authors: ZHANG Yongwei
Published: March 2024

Label correlations are an essential technique for data mining that solves the possible correlation problem between different labels in multi-label classification. Although this technique is widely used in multi-label classification problems, batch learning deals with most issues, which consumes a lot of time and space resources. Unlike traditional batch learning methods, online learning represents a promising family of efficient and scalable machine learning algorithms for large-scale datasets. However, existing online learning research has done little to consider correlations between labels. On the basis of existing research, this paper proposes a multi-label online learning algorithm based on label correlations by maximizing the interval between related labels and unrelated labels in multi-label samples. We evaluate the performance of the proposed algorithm on several public datasets. Experiments show the effectiveness of our algorithm.
Comprehensive Analysis of the Role of Forkhead Box J3 (FOXJ3) in Human Cancers
Authors: YANG Yang , LI Yulong , WANG Xiaoli
Published: March 2024

Forkhead box J3 (FOXJ3) is a member of the forkhead box (Fox) family. Recently, increasing evidence has revealed the relationship between Fox family members and cancer.FOXJ3is involved in various types of cancer, including lung cancer, tongue squamous carcinoma, and prostate cancer; however, a comprehensive pan-cancer analysis ofFOXJ3remains lacking. Here, we explored the function ofFOXJ3across cancers using online websites and databases including TIMER2.0, SangerBox, UALCAN, GEPIA2.0, cBioPortal, CancerSEA,STRING, BioGRID and Metascape to analyze the role ofFOXJ3in cancers. Abnormal expression ofFOXJ3was found in various tumors. The genetic alteration percentage in tumors was determined, and elevatedFOXJ3expression was found to be associated with worse overall survival in brain lower grade glioma(LGG), liver hepatocellular carcinoma (LIHC), sarcoma (SARC) and thyroid carcinoma. ElevatedFOXJ3expression was related to worse prognosis with disease-free survival in adrenocortical carcinoma, LGG and LIHC.FOXJ3expression was related to immune infiltration in several cancers. Enrichment analysis showed that histone modification, the TGF-β signaling pathway, and chromatin organization were the top three enriched ontology clusters of the top 100 similar genes ofFOXJ3. Our pan-cancer analysis provides comprehensive insights intoFOXJ3from the perspective of bioinformatics in different cancers, where it serves as a potential biomarker for prognosis, especially in LGG and LIHC.FOXJ3is also correlated with immune infiltrates in certain human tumors.