bluuebunny/crossref_metadata_2025 huggingface dataset:
Overestimation of Mangroves Deterioration From Sea Level Rise in Tropical Deltas
Authors: Dai Zhijun , Long Chuqi , Mei Xuefei , Fagherazzi Sergio , Xiong Yuan
Published: October 2024

Mangrove forests are critical coastal ecosystems that provide great socio‐ecological services, which are also highly vulnerable to climate change, particularly to sea level rise (SLR). Here we assess changes in mangrove forests in four distinct river/tide/wave‐dominant large deltas along the Indo‐Pacific coast based on 1,336 remote sensing images by machine learning techniques. We find that mangroves are migrating seaward at a rate of 18% ± 12% m/yr, which can offset landward mangroves loss, 67% of which caused by land use conversion. The fact that mangroves are expanding seaward with accretion rates exceeding SLR suggests that climate change has not yet triggered substantial loss in deltaic mangrove forests. Assuming that present environmental conditions do not change and that sediment and organic deposition in the deltaic topsets match SLR rates, we project that 90% of deltaic mangrove forests may start to retreat after 132–194 years. Early inundation of mangroves will occur in wave‐dominated delta.
Characterizing Wet Season Precipitation in the Central Amazon Using a Mesoscale Convective System Tracking Algorithm
Authors: Tai Sheng‐Lun , Feng Zhe , Marquis James , Fast Jerome
Published: October 2024

To comprehensively characterize convective precipitation in the central Amazon region, we utilize the Python FLEXible object TRacKeR (PyFLEXTRKR) to track mesoscale convective systems (MCSs) observed through satellite measurements and simulated by the Weather Research and Forecasting model at a convection‐permitting resolution. This study spans a 2‐month period during the wet seasons of 2014 and 2015. We observe a strong correlation between the MCS track density and accumulated precipitation in the Amazon basin. Key factors contributing to precipitation, such as MCS properties (number, size, rainfall intensity, and movement), are thoroughly examined. Our analysis reveals that while the overall model produces fewer MCSs with smaller mean sizes compared to observations, it tends to overpredict total precipitation due to excessive rainfall intensity for heavy rainfall events (≥10 mm hr−1). These biases in simulated MCS properties could vary with the constraints on the convective background environment. Moreover, while the wet bias from heavy (convective) rainfall outweighs the dry bias in light (stratiform) rainfall, the latter can be crucial, particularly when MCS cloud cover is significantly underestimated. A case study for 1 April 2014 highlights the influence of environmental conditions on the MCS lifecycle and identifies an unrealistic model representation in both stratiform and convective precipitation features.
Interdecadal Springtime Aerosol Increase in the North Indian Ocean Observed From the Satellite AVHRR Instrument
Authors: Zhang Yongsheng , Frech James , Zhao Xuepeng , Zhang Huai‐min
Published: October 2024

A 38‐year aerosol optical thickness (AOT) satellite product from the Advanced Very High‐Resolution Radiometer (AVHRR) is used to investigate the aerosol variabilities in the North Indian Ocean (NIO). A dipolar mode with a notable meridional contrast between the equatorial and northern NIO is revealed by the second mode of Empirical Orthogonal Function (EOF) analysis with a sharp rise over the Arabian Sea (AS) and Bay of Bengal (BoB) since 2002. Our results show that the aerosol dipolar variation is primarily modulated by an El Niño–Southern Oscillation (ENSO) during 1983–2001 (ID1) and by a warm phase of Atlantic Multi‐decadal Oscillation (AMO) during 2002–2020 (ID2), leading to a dry‐and‐warming condition spanning the coasts of East Africa, the Arabian Peninsula (AP), and South Asia (SA) that favors increasing aerosol emission and a longer life cycle in the upstream regions. A warm phase of the AMO tends to excite an anomalous cyclone in western Siberia and reinforces anticyclonic circulation in the Tibetan Plateau. Correlation analyses between the second EOF mode time series and other parameters in ID1 and ID2 show that an interannual dry‐and‐warming condition over the AP–SA is associated with a noticeable north‐south contrast of convection between the equatorial NIO and AP–SA in ID1. But in ID2, a zonal contrast of anomalous convective activities between the AP–SA and the BoB‐South China Sea is dominant, partially due to the warming AMO, which aids the development of anticyclonic cells over the TP and the strengthened subtropical westerly jet streams.
Atomistic simulations of polysaccharide materials for insights into their crystal structure, nanostructure, and dissolution mechanism
Authors: Uto Takuya
Published: October 2024

Crystalline polysaccharides are abundant in nature and can be transformed into highly functional materials. However, the molecular basis for the formation of higher-order structures remains unclear. Computer simulation is an advanced tool for modeling macromolecular structures, and the atomistic simulations provide valuable information on the crystalline polysaccharides. Fiber deformation, crystalline transition, and novel nanostructures of cellulose were characterized through molecular dynamics simulations and density functional theory calculations of models of molecular chain sheets extracted from the crystal structure of the cellulose polymorphs. Extended ensemble molecular dynamics simulations were applied to analyze the artificial crystal structure of non-natural amylose analog polysaccharides, revealing the hexagonal packing of double helices through the self-assembly of molecular chains dispersed in aqueous solution. Dissolution simulations of the cellulose and chitin crystalline fibers revealed that the anions of ionic liquids, with their solvation power, played a key role in the cleavage of intermolecular hydrogen bonds in the crystal structure, whereas the cations contributed to irreversible molecular chain dispersion. The good correlation between the actual solubility of polysaccharides and the predicted number of intermolecular hydrogen bonds prompted the development of a platform that combined simulations and machine learning for high-throughput screening of solvents for cellulose and chitin.
Molecular composition of skeletal muscle in infants and adults: a comparative proteomic and transcriptomic study
Authors: Schaiter Alexander , Hentschel Andreas , Kleefeld Felix , Schuld Julia , Umathum Vincent , Procida-Kowalski Tara , Nelke Christopher , Roth Angela , Hahn Andreas , Krämer Heidrun H. , Ruck Tobias , Horvath Rita , van der Ven Peter F. M. , Bartkuhn Marek , Roos Andreas , Schänzer Anne
Published: October 2024

To gain a deeper understanding of skeletal muscle function in younger age and aging in elderly, identification of molecular signatures regulating these functions under physiological conditions is needed. Although molecular studies of healthy muscle have been conducted on adults and older subjects, there is a lack of research on infant muscle in terms of combined morphological, transcriptomic and proteomic profiles. To address this gap of knowledge, we performed RNA sequencing (RNA-seq), tandem mass spectrometry (LC–MS/MS), morphometric analysis and assays for mitochondrial maintenance in skeletal muscle biopsies from both, infants aged 4–28 months and adults aged 19–65 years. We identified differently expressed genes (DEGs) and differentially expressed proteins (DEPs) in adults compared to infants. The down-regulated genes in adults were associated with functional terms primarily related to sarcomeres, cellular maintenance, and metabolic, immunological and developmental processes. Thus, our study indicates age-related differences in the molecular signatures and associated functions of healthy skeletal muscle. Moreover, the findings assert that processes previously associated solely with aging are indeed part of development and healthy aging. Hence, combined findings of this study also indicate that age-dependent controls are crucial in muscle disease studies, as otherwise the comparative results may not be reliable.
Development of novel rectal/uterine clamping device
Authors: Urabe Shoichiro , Hata Taishi , Kobayashi Eiji , Ishii Yuji , Ushimaru Yuki , Takeda Mitsunobu , Sekido Yuki , Hata Tsuyoshi , Hamabe Atsushi , Ogino Takayuki , Miyoshi Norikatsu , Uemura Mamoru , Yamamoto Hirofumi , Doki Yuichiro , Eguchi Hidetoshi , Nakajima Kiyokazu
Published: October 2024

We developed a novel clamping device for laparoscopic surgery, free from conventional pinch structure, capable of uniformly occluding any ductal organ. This study aimed to evaluate performance of the new clamper compared to the pinch-type clamper. The new clamper consists of two metal bars with ties at each end, which enables parallel clamping. A resected porcine stomach was used, with an infusion tube at the anal end to increase intra-luminal pressure. The oral side of the stomach was clamped with either the new clamper or the pinch-type clamper, and their performances were evaluated in qualitative and semi-quantitative manner. Qualitative evaluation involved imaging the clamping site at intra-gastric pressures from 0 to 15 mmHg using microfocus computed tomography. The new clamper showed no gap even under increased intra-luminal pressure, while the pinch-type clamper showed a gap on the distal side. Quantitative evaluation measured bursting pressure under continuous air insufflation. Air leakages were observed in the new clamper at higher intra-luminal pressures than in the pinch-type clamper (46.1 mmHg vs. 13.6 mmHg, P < 0.01). Our new clamping device showed superior performance in preclinical setting compared to the conventional pinch-type clamper. We are currently working on its design freezing and aiming for early commercialization.
Sexual dimorphism in a mouse model of Friedreich’s ataxia with severe cardiomyopathy
Authors: Salinas Lili , Montgomery Claire B. , Figueroa Francisco , Thai Phung N. , Chiamvimonvat Nipavan , Cortopassi Gino , Dedkova Elena N.
Published: October 2024

Friedreich’s ataxia (FA) is an autosomal recessive disorder caused by reduced frataxin (FXN) expression in mitochondria, where the lethal component is cardiomyopathy. Using the conditional Fxnflox/null::MCK-Cre knock-out (Fxn-cKO) mouse model, we discovered significant sex differences in the progression towards heart failure, with Fxn-cKO males exhibiting a worse cardiac phenotype, low survival rate, kidney and reproductive organ deficiencies. These differences are likely due to a decline in testosterone in Fxn-cKO males. The decrease in testosterone was related to decreased expression of proteins involved in cholesterol transfer into the mitochondria: StAR and TSPO on the outer mitochondrial membrane, and the cholesterol side-chain cleavage enzyme P450scc and ferredoxin on the inner mitochondrial membrane. Expression of excitation-contraction coupling proteins (L-type calcium channel, RyR2, SERCA2, phospholamban and CaMKIIδ) was decreased significantly more in Fxn-cKO males. This is the first study that extensively investigates the sexual dimorphism in FA mouse model with cardiac calcium signaling impairment.
Multiple measures for self-identification improve matching donors with patients in unrelated hematopoietic stem cell transplant
Authors: Damotte Vincent , Zhao Chao , Lin Chris , Williams Eric , Louzoun Yoram , Madbouly Abeer , Kotlarz Rochelle , McDaniel Marissa , Norman Paul J. , Wang Yong , Maiers Martin , Hollenbach Jill A.
Published: October 2024

Background

Questions persist around whether and how to use race or geographic ancestry in biomedical research and medicine, but these forms of self-identification serve as a critical tool to inform matching algorithms for human leukocyte antigen (HLA) of varying levels of resolution for unrelated hematopoietic stem cell transplant in large donor registries.

Methods

Here, we examined multiple self-reported measures of race and ancestry from a survey of a cohort of over 100,000 U.S. volunteer bone marrow donors alongside their high-resolutionHLAgenotype data.

Results

We find that these self-report measures are often non-overlapping, and that no single self-reported measure alone provides a better fit toHLAgenetic ancestry than a combination including both race and geographic ancestry. We also found that patterns of reporting for race and ancestry appear to be influenced by participation in direct-to-consumer genetic ancestry testing.

Conclusions

While these data are not used directly in matching for transplant, our results demonstrate that there is a place for the language of both race and geographic ancestry in the critical process of facilitating accurate prediction ofHLAin the donor registry context.
Modulating the photolysis of aryl azides in a supramolecular host to develop photoactivatable fluorophores
Authors: Qiu Xujun , Pohl Eric , Jung André , Cai Qianyu , Su Haopu , Fuhr Olaf , Schepers Ute , Bräse Stefan
Published: October 2024

The supramolecular host cucurbit[7]uril selectively directs the photolysis of aryl azides to emissive carbolines, highlighting the potential of developing photoactivatable fluorophores using a host–guest strategy.
CRISPR–Cas12a detection of DNA glycosylases via DNA modification switching
Authors: Li Youxian , Yang Xiaoquan , Dong Yi , Wang Jiaqi , Liu Chaoxing
Published: October 2024

A programmable CRISPR–Cas12a system utilizing DNA modification switching enhances DNA glycosylase detection, overcoming the limitation of non-nucleic acid diagnostics to aptamers.
Examination of photoinduced radicals in two crystal forms of triphenylamine bis-urea macrocycles
Authors: Islam Md Faizul , Wijesekera Gamage Isuri P. , Sindt Ammon J. , Smith Mark D. , Shimizu Linda S.
Published: October 2024

The structures and photoinduced radical (PIR) percentages of two crystalline solvates of unsubstituted triphenylamine bis-urea macrocycles are compared. Upon activation, both afford similar structures with higher PIR %.
Highly efficient ultraviolet and visible light emissions from upconversion transitions in Ho/Tm/Yb co-doped lutecia-stabilized zirconia single crystals excited by a 980 nm laser
Authors: Lu Kan , Zhang Qifan , Kong Juan , Hao Yan , Wu Wenxia , Wang Yazhao , Lin Haibo , Xu Shoulei , Deng Wen
Published: October 2024

High-quality LSZ and LSZ:Yb0.25Tm0.5Ho0.03 single crystals were grown for the first time. Under 980 nm excitation, LSZ:Yb0.25Tm0.5Ho0.03 crystal has high efficiency over YSZ:Yb0.25Tm0.5Ho0.03 crystal in ultraviolet and visible light emissions.
Thermally stable Cr3+-activated silicate phosphors for plant-growth LEDs and three-mode optical thermometry
Authors: Ma Rongbo , Zhang Tingting , Cao Bin , Gong Xinyong , Deng Chaoyong , Huang Weichao
Published: October 2024

A Cr3+-activated silicate phosphor is prepared with good thermal stability, which exhibits excellent properties for three-mode luminescent thermometry and plant-growth LED applications.
Mixed-ligand based water-stable Mn(ii)-MOF for quick, sensitive, and reusable IFE-PET-RET facilitated detection of formaldehyde and Cr(vi)-oxoanions in real-field samples like food and industrial water: experimental and theoretical insights
Authors: Mondal Udayan , Nag Somrita , Pal Rajeshwari , Banerjee Priyabrata
Published: October 2024

We report the luminescence-based detection of Group-1 carcinogen formaldehyde (FA) and Cr(vi)-oxoanions with a mesoporous Mn(ii)-MOF (1), featuring a uninodal 4-c net topology and linear 1D square channels forming a polymeric 2D network.
A supported Au/HZSM-5 catalyst for toluene removal by air plasma catalytic oxidation using the cycled storage-discharge (CSD) mode
Authors: Zhou Amin , Li Xiao-Song , Liu Jing-Lin , Di Lan-Bo , Zhu Ai-Min
Published: October 2024

A Au/HZSM-5 catalyst was prepared and exhibited nearly 100% C7H8 conversion and CO2 selectivity in air plasma catalytic C7H8 oxidation.
A novel, glutathione-activated prodrug of pimasertib loaded in liposomes for targeted cancer therapy
Authors: Amenta Arianna , Comi Susanna , Kravicz Marcelo , Sesana Silvia , Antoniou Antonia , Passarella Daniele , Seneci Pierfausto , Pellegrino Sara , Re Francesca
Published: October 2024

A novel, glutathione-activated prodrug of pimasertib (PROPIMA) has been developed. PROPIMA showed ability to inhibit tumour cell migration and proliferation controlled over time, while also achieving a high incorporation rate into liposomes.
Discovery of N-substituted-2-oxoindolin benzoylhydrazines as c-MET/SMO modulators in EGFRi-resistant non-small cell lung cancer
Authors: Tomassi Stefano , Natale Benito , Roggia Michele , Amato Luisa , De Rosa Caterina , Della Corte Carminia Maria , Baglini Emma , Amendola Giorgio , Messere Anna , Di Maro Salvatore , Barresi Elisabetta , Da Settimo Federico , Trincavelli Maria Letizia , Ciardiello Fortunato , Taliani Sabrina , Morgillo Floriana , Cosconati Sandro
Published: October 2024

Non-small cell lung cancer (NSCLC), the leading cause of cancer-related mortality worldwide, poses a formidable challenge due to its heterogeneity and the emergence of resistance to targeted therapies.
Advancing the understanding of M–O covalency in isostructural M–OSiMe3 (M = Ce, Th, U) complexes
Authors: Liu Kang , Chi Xiaowang , Guo Yan , Hu Kongqiu , Mei Lei , Yu Jipan , Shi Weiqun
Published: October 2024

A series of isostructural 4f and 5f complexes are synthesized. The theoretical calculation shows that the covalency of M–O bonding follows the trend of Ce–O < Th–O < U–O.
Synthesis of N-heterocyclic amides from imidazoheterocycles through convergent paired electrolysis
Authors: Leclercq Elise , Chevet Laura , David Nicolas , Durandetti Muriel , Chausset-Boissarie Laëtitia
Published: October 2024

Herein, we present a novel electrochemical approach for the synthesis of N-heterocyclic amides with moderate to excellent yields in batch and flow.
Visible light-promoted C3–H alkoxycarbonylation of quinoxalin-2(1H)-ones or coumarins with alkyloxalyl chlorides
Authors: Lin Yanchun , Zhou Xi , Zheng Yixuan , Chen Bingran , Liu Yang , Zhang Yi , Yan Qiongjiao , Wang Wei , Chen Fener
Published: October 2024

A visible light-mediated C3–H alkoxycarbonylation between alkyloxalyl chlorides and quinoxalinones or coumarins was developed. This protocol allowed the formation of quinoxaline-3-carbonyl and coumarin-3-carbonyl compounds under mild conditions.
Adhesion of a nematic elastomer cylinder
Authors: Maghsoodi Neda , Bhattacharya Kaushik
Published: October 2024

This study reveals that the soft elasticity of polydomain nematic elastomers dramatically affects the interfacial stress distribution and the adhesion of a nematic elastomer cylinder adhered to a rigid substrate.
Nanoconfinement effects on the dynamics of an ionic liquid-based electrolyte probed by multinuclear NMR
Authors: Filippov Andrei , Rudakova Maiia , Archipov Victor P. , Shah Faiz Ullah
Published: October 2024

Diffusivity is controlled by exchange of ions between “narrow” and “large” pores that results in an abnormal temperature variation. Li+ ions are solvated inside the porous glasses and their diffusivity remains slower as compared to the organic ions.
C4 grasses employ distinct strategies to acclimate rubisco activase to heat stress
Authors: Stainbrook Sarah C. , Aubuchon Lindsey N. , Chen Amanda , Johnson Emily , Si Audrey , Walton Laila , Ahrendt Angela J. , Strenkert Daniela , Jez Joseph M.
Published: October 2024

Rising temperatures due to the current climate crisis will soon have devastating impacts on crop performance and resilience. In particular, CO2 assimilation is dramatically limited at high temperatures. CO2 assimilation is accomplished by rubisco, which is inhibited by the binding of inhibitory sugar phosphates to its active site. Plants therefore utilize the essential chaperone rubisco activase (RCA) to remove these inhibitors and enable continued CO2 fixation. However, RCA does not function at moderately high temperatures (42°C), resulting in impaired rubisco activity and reduced CO2 assimilation. We set out to understand temperature-dependent RCA regulation in four different C4 plants, with a focus on the crop plants maize (two cultivars) and sorghum, as well as the model grass Setaria viridis (setaria) using gas exchange measurements, which confirm that CO2 assimilation is limited by carboxylation in these organisms at high temperatures (42°C). All three species express distinct complements of RCA isoforms and each species alters the isoform and proteoform abundances in response to heat; however, the changes are species-specific. We also examine whether the heat-mediated inactivation of RCA is due to biochemical regulation rather than simple thermal denaturation. We reveal that biochemical regulation affects RCA function differently in different C4 species, and differences are apparent even between different cultivars of the same species. Our results suggest that each grass evolved different strategies to maintain RCA function during stress and we conclude that a successful engineering approach aimed at improving carbon capture in C4 grasses will need to accommodate these individual regulatory mechanisms.
A conceptual framework proposal for the implementation of Prognostic and Health Management in production systems
Authors: Abbate Raffaele , Franciosi Chiara , Voisin Alexandre , Fera Marcello
Published: October 2024

Prognostic and Health Management (PHM) is an emerging maintenance concept that is highly regarded by the scientific community and practitioners, as its adoption can bring economic, technical and environmental benefits to a company. PHM fully reflects the smart maintenance paradigm encompassing data collection, data manipulation, state detection, health assessment, prognostic assessment and advisory generation. Despite the undeniable benefits, there is still a large gap between the scientific and the real world. Several authors have investigated on the barriers to PHM implementation for companies, highlighting among them the lack of systematic approaches to its design and implementation. As a first contribution to this topic, the authors conducted a systematic literature review (SLR) to investigate the use of Decision Support Systems (DSSs) to support the PHM implementation. The SLR highlighted that few DSS had been developed and were limited to critical unit identification, maintenance strategy selection and data acquisition phase of PHM. Therefore, a conceptual framework for PHM implementation was provided as a second contribution. This framework summarises the decisions that should be addressed by a practitioner wishing to implement PHM services; moreover, it could lay the foundations for the development/improvement of the missing/existing DSSs for PHM implementation.
Design and implementation of passive impedance adapter to damp resonances between VSC‐HVDC and AC systems
Authors: Zou Changyue , Feng Junjie , Zhao Xiaobin , Yuan Yi , Hou Ting
Published: October 2024

It has been known that resonances often occur when high‐voltage direct current (HVDC) systems are connected into the AC system via voltage‐source converters (VSCs). The resonances may lead to system failure and even damage primary equipment under some severe conditions. However, the existing damping methods are inadequate to ensure the system is always stable. To solve it, this article introduces the passive impedance adapter (PIA) in parallel with VSC to compensate the negative impedance of VSC‐HVDC system especially at mid‐ and high‐frequency ranges. A novel design and implementation method for the PIA is then proposed with the reduced volume and power loss to ensure the whole system impedance always positive. By this way, no resonance exists and the system is stable under any practical condition, such as the different cable lengths and impedances. Finally, a simulation platform is built to verify the effectiveness of the proposed PIA method in compensating the VSC‐HVDC impedance.
Microlensing analysis of 14.5-year light curves in SDSS J1004+4112: Quasar accretion disk size and intracluster stellar mass fraction
Authors: Forés-Toribio R. , Muñoz J. A. , Fian C. , Jiménez-Vicente J. , Mediavilla E.
Published: October 2024

Context. The gravitational lens system SDSS J1004+4112 was the first known example of a quasar lensed by a galaxy cluster. The interest in this system has been renewed following the publication of r-band light curves spanning 14.5 years and the determination of the time delays between the four brightest quasar images.

Aims. We constrained the quasar accretion disk size and the fraction of the lens mass in stars using the signature of microlensing in the quasar image light curves.

Methods. We built the six possible histograms of microlensing magnitude differences between the four quasar images and compared them with simulated model histograms, using a χ2 test to infer the model parameters.

Results. We infer a quasar disk half-light radius of
R1/2 = (0.70 ± 0.04)RE = (6.4 ± 0.4) √M/0.3M⊙
light-days at 2407 Å in the rest frame and stellar mass fractions at the quasar image positions of αA > 0.059,
αB = 0.056+0.021-0.027,
αC = 0.030+0.031-0.021, and
αD = 0.072+0.034-0.016.

Conclusions. The inferred disk size is broadly compatible with most previous estimates, and the stellar mass fractions are within the expected ranges for galaxy clusters. In the region where image C lies, the stellar mass fraction is compatible with a stellar contribution from the brightest cluster galaxy, galaxy cluster members, and intracluster light, but the values at images B, D, and especially A are slightly larger, possibly suggesting the presence of extra stellar components.
The M•–σe relation for local type 1 AGNs and quasars
Authors: Molina J. , Ho L. C. , Knudsen K. K.
Published: October 2024

We analyzed Multi Unit Spectroscopic Explorer observations of 42 local z ≲ 0.1 type 1 active galactic nucleus (AGN) host galaxies taken from the Palomar-Green quasar sample and the close AGN reference survey. Our goal was to study the relation between the black hole mass (M•) and bulge stellar velocity dispersion (σe) for type 1 active galaxies. The sample spans black hole masses of 106.0 − 109.2 M⊙, bolometric luminosities of 1042.9 − 1046.0 erg s−1, and Eddington ratios of 0.006 − 1.2. We avoided AGN emission by extracting the spectra over annular apertures. We modeled the calcium triplet stellar features and measured stellar velocity dispersions of σ* = 60 − 230 km s−1 for the host galaxies. We find stellar velocity dispersion values in agreement with previous measurements for local (z ≲ 0.1) AGN host galaxies, but slightly lower compared with those reported for nearby X-ray-selected type 2 quasars. Using a novel annular aperture correction recipe to estimate σe from σ* that considers the bulge morphology and observation beam-smearing, we estimate flux-weighted σe = 60 − 250 km s−1. If we consider the bulge type when estimating M•, we find no statistical difference between the distributions of AGN hosts and the inactive galaxies on the M•–σe plane for M• ≲ 108 M⊙. Conversely, if we do not consider the bulge type when computing M•, we find that both distributions disagree. We find no correlation between the degree of offset from the M•–σe relation and Eddington ratio for M• ≲ 108 M⊙. The current statistics preclude firm conclusions from being drawn for the high-mass range. We argue these observations support notions that a significant fraction of the local type 1 AGNs and quasars have undermassive black holes compared with their host galaxy bulge properties.
Charting the main sequence of star-forming galaxies out to redshifts z ≲ 5.7
Authors: Koprowski M. P. , Wijesekera J. V. , Dunlop J. S. , McLeod D. J. , Michałowski M. J. , Lisiecki K. , McLure R. J.
Published: October 2024

We present a new determination of the star-forming main sequence (MS), obtained through stacking 100k K-band-selected galaxies in the far-infrared (FIR) Herschel and James Clerk Maxwell Telescope (JCMT) imaging. By fitting the dust emission curve to the stacked FIR photometry, we derive the IR luminosities (LIR), and hence the star formation rates (SFRs) out to z ≲ 5.7. The functional form of the MS is found, with the linear SFR-M* relation that flattens at high stellar masses and the normalization that increases exponentially with redshift. We derive the corresponding redshift evolution of the specific star formation rate (sSFR) and compare our findings with the recent literature. We find our MS to be exhibiting slightly lower normalization at z ≲ 2 and to flatten at somewhat larger stellar masses at high redshifts. By deriving the relationship between the peak dust temperature (Td) and redshift, where Td increases linearly from ∼20 K at z = 0.5 to ∼50 K at z = 5, we conclude that the apparent inconsistencies in the shapes of the MS are most likely caused by the different dust temperatures assumed when deriving SFRs in the absence of FIR data. Finally, we investigate the derived shape of the star-forming MS by simulating the time evolution of the observed galaxy stellar mass function (GSMF). While the simulated GSMF is in good agreement with the observed one, some inconsistencies persist. In particular, we find the simulated GSMF to be slightly overpredicting the number density of low-mass galaxies at z ≳ 2.
S-process nucleosynthesis in chemically peculiar binaries
Authors: Dimoff A. J. , Hansen C. J. , Stancliffe R. , Kubátová B. , Stateva I. , Kučinskas A. , Dobrovolskas V.
Published: October 2024

Context. Around half of the heavy elements in the Universe are formed through the slow neutron capture (s-) process, which takes place in thermally pulsing asymptotic giant branch (AGB) stars with masses of 1 − 6 M⊙. The nucleosynthetic imprint of the s-process can be studied by observing the material on the surface of binary barium (Ba), carbon (C), CH, and carbon-enhanced metal-poor (CEMP) stars.

Aims. We study the s-process by observing the luminous components of binary systems polluted by a previous AGB companion. Our radial velocity (RV) monitoring program establishes an ongoing collection of binary stars exhibiting enrichment in s-process material for the study of elemental abundances, the production of s-process material, and binary mass transfer.

Methods. From high-resolution optical spectra, we measured RVs for 350 stars and derived stellar parameters for approximately 150 stars using ATHOS. For a subsample of 24 chemically interesting stars, we refined our atmospheric parameters using ionization and excitation balance with the Xiru program. We used the MOOG code to compute one-dimensional local thermodynamic equilibrium (1D-LTE) abundances of carbon, magnesium, s-process elements (Sr, Y, Zr, Mo, Ba, La, Ce, Nd, Pb), and Eu to investigate neutron capture events and stellar chemical composition. We estimated dynamical stellar masses via orbital optimization using Markov chain Monte Carlo techniques in the ELC program, and we compared our results with low-mass AGB models in the FUll-Network Repository of Updated Isotopic Tables & Yields (FRUITY) database.

Results. In our abundance subsample, we find enhancements in s-process material in spectroscopic binaries, a signature of AGB mass transfer. We add the element Mo to the abundance patterns, and for 12 stars we add Pb detections or upper limits, as these are not known in the literature. Computed abundances are in general agreement with the literature. Comparing our abundances to dilution-modified FRUITY yields, we find correlations in s-process enrichment and AGB mass, which are supported by dynamical modeling from RVs.

Conclusions. From our high-resolution observations, we expand heavy element abundance patterns and highlight binarity in our chemically interesting systems. We find trends in s-process element enhancement from AGB stars, and agreement between theoretical and dynamically modeled masses. We investigate evolutionary stages for a small subset of our stars.
Impact of H I cooling and study of accretion disks in asymptotic giant branch wind-companion smoothed particle hydrodynamic simulations
Authors: Malfait J. , Siess L. , Esseldeurs M. , De Ceuster F. , Wallström S. H. J. , de Koter A. , Decin L.
Published: October 2024

Context. High-resolution observations reveal that the outflows of evolved low- and intermediate-mass stars harbour complex morphological structures that are linked to the presence of one or multiple companions. Hydrodynamical simulations provide a way to study the impact of a companion on the shaping of the asymptotic giant branch (AGB) star out-flow.

Aims. Using smoothed particle hydrodynamic (SPH) simulations of an AGB star undergoing mass loss, which also has a binary companion, we study the impact of including H I atomic line cooling on the flow morphology. We also study how this affects the properties of the accretion disks that form around the companion.

Methods. We used the PHANTOM code to perform high-resolution 3D SPH simulations of the interaction of a solar-mass companion with the outflow of an AGB star, using different wind velocities and eccentricities. We compared the model properties, computed with and without the inclusion of H I cooling.

Results. The inclusion of H I cooling produces a sizeable decrease in the temperature, up to one order of magnitude, in the region closely surrounding the companion star. As a consequence, the morphological irregularities and relatively energetic (bipolar) outflows that were obtained without H I cooling no longer appear. In the case of an eccentric orbit and a low wind velocity, these morphologies are still highly asymmetric, but the same structures recur at every orbital period, making the morphology more regular. Flared accretion disks, with a (sub-)Keplerian velocity profile, are found to form around the companion in all our models with H I cooling, provided the accretion radius is small enough. The disks have radial sizes ranging from about 0.4 to 0.9 au and masses around 10−7−10−8 M⊙. For the considered wind velocities, mass accretion onto the companion is up to a factor of 2 higher than predicted by the standard Bondi Hoyle Littleton rate, ranging between ~4 to 21% of the AGB wind mass loss rate. The lower the wind velocity at the location of the companion, the larger and the more massive the disk and the higher the mass accretion efficiency. In eccentric systems, the disk size, disk mass, and mass accretion efficiency vary, depending on the orbital phase.

Conclusions. H I cooling is an essential ingredient to properly model the medium around the companion where density-enhanced wind structures form and it favours the formation of an accretion disk.
Indications of magnetic accretion in Swift J0826.2−7033
Authors: Rawat Nikita , De Martino Domitilla , Mukai Koji , Falanga Maurizio , Masetti Nicola , Pandey Jeewan C.
Published: October 2024

We present our findings from the first long X-ray observation of the hard X-ray source Swift J0826.2−7033 with XMM-Newton, which has shown characteristics of magnetic accretion. The system appears to have a long orbital period (∼7.8 h) accompanied by short timescale variabilities, which we tentatively interpret as the spin and beat periods of an intermediate polar. These short- and long-timescale modulations are energy-independent, suggesting that photoelectric absorption does not play any role in producing the variabilities. If our suspected spin and beat periods are true, then Swift J0826.2−7033 accretes via disc-overflow with an equal fraction of accretion taking place via disc and stream. The XMM-Newton and Swift-BAT spectral analysis reveals that the post-shock region in Swift J0826.2−7033 has a multi-temperature structure with a maximum temperature of ∼43 keV, which is absorbed by a material with an average equivalent hydrogen column density of ∼1.6 × 1022 cm−2 that partially covers ∼27% of the X-ray source. The suprasolar abundances, with hints of an evolved donor, collectively make Swift J0826.2−7033 an interesting target, which likely underwent a thermal timescale mass transfer phase.
Modeling long carbon-chain species formation with porous multiphase models
Authors: Song Ziwen , Chang Qiang , Meng Qingkuan , Zhang Xia
Published: October 2024

Context. Recent studies show that multiphase models trap too many volatile species such as CH4 inside ice mantles, so they usually underestimate the abundances of long carbon-chain species observed toward warm carbon-chain chemistry (WCCC) sources.

Aims. We propose a new multiphase model that allows more volatile species to diffuse out of the ice mantle upon warming. The new multiphase model is used to study the synthesis of long carbon-chain molecules in WCCC sources.

Methods. We included porous structure in the ice mantles. The porous structure can enlarge the active layers of ice mantles so that fewer volatile species are trapped. The porous multiphase models were simulated using an accelerated Gillespie algorithm.

Results. The abundances of long carbon-chain species predicted by the porous multiphase models can be more than one order of magnitude higher than those predicted by the multiphase model at temperatures relevant to WCCC sources. Moreover, the porous multiphase models predict more abundant long carbon-chain species as the porosity of the ice mantles increases. On the other hand, the two-phase model still estimates higher long carbon-chain species abundances than the porous multiphase models do. The abundances of long carbon-chain species predicted by our porous multiphase models agree reasonably well with observations toward three WCCC sources, L483, L1527, and B228.

Conclusions. Our porous multiphase model solves the problem of too many volatile species being trapped in ice mantles in the multiphase models.
Identifying the mechanisms of water maser variability during the accretion burst in NGC6334I
Authors: Vorster J. M. , Chibueze J. O. , Hirota T. , MacLeod G. C. , van der Walt D. J. , Vorobyov E. I. , Sobolev A. M. , Juvela M.
Published: October 2024

Context. High-mass young stellar objects gain most of their mass in short intense bursts of accretion. Maser emission is an invaluable tool in discovering and probing these accretion bursts.

Aims. Our aim was to observe the 22 GHz water maser response induced by the accretion burst in NGC6334I-MM1B and to identify the underlying maser variability mechanisms.

Methods. We report seven epochs of very long baseline interferometry (VLBI) observations of 22 GHz water masers in NGC6334I with the VLBI Exploration of Radio Astrometry (VERA) array, from 2014 to 2016, spanning the onset of the accretion burst in 2015.1. We also report 2019 Atacama Large Millimeter/submillimeter Array (ALMA) observations of 321 GHz water masers and 22 GHz single-dish maser monitoring by the Hartebeesthoek Radio Astronomical Observatory (HartRAO). We analysed long-term variability patterns and used proper motions with the 22 GHz to 321 GHz line ratio to distinguish between masers in non-dissociative C-shocks and dissociative J-shocks. We also calculated the burst-to-quiescent variance ratio of the single-dish time series.

Results. We detected a water maser distribution resembling a bipolar outflow morphology. The constant mean proper motion before and after the burst indicates that maser variability is due to excitation effects from variable radiation rather than jet ejecta. For the whole region, we find that the flux density variance ratio in the single-dish time series can identify maser efficiency variations in 22 GHz masers. The northern region, CM2-W2, is excited in C-shocks and showed long-term flaring with velocity-dependent excitation of new maser features after the onset of the burst. We propose that radiative heating of H2 due to high-energy radiation from the accretion burst be the main mechanism for the flaring in CM2-W2. The southern regions are excited by J-shocks, which have shown short-term flaring and dampening of water masers. We attribute the diverse variability patterns in the southern regions to the radiative transfer of the burst energy in the complex source geometry.

Conclusions. Our results indicate that the effects of source geometry, shock type, and incident radiation spectrum are fundamental factors affecting 22 GHz maser variability. Investigating water masers in irradiated shocks will improve their use as a diagnostic in time-variable radiation environments, such as accretion bursting sources.
Alcock–Paczyński effect on void-finding
Authors: Radinović Slađana , Winther Hans A. , Nadathur Seshadri , Percival Will J. , Paillas Enrique , Sohrab Fraser Tristan , Massara Elena , Woodfinden Alex
Published: October 2024

Under the assumption of statistical isotropy, and in the absence of directional selection effects, a stack of voids is expected to be spherically symmetric, which makes it an excellent object to use for an Alcock–Paczyński (AP) test. This test is commonly carried out using the void-galaxy cross-correlation function (CCF), which has emerged as a competitive probe, especially in combination with the galaxy-galaxy auto-correlation function. Current studies of the AP effect around voids assume that void-centre positions are influenced by the choice of fiducial cosmology in the same way as galaxy positions. We show that this assumption, though prevalent in the literature, is complicated by the response of void-finding algorithms to shifts in tracer positions. Using stretched simulation boxes to emulate the AP effect, we investigate how the void-galaxy CCF changes due to its presence, revealing an additional effect imprinted in the CCF that must be accounted for. The effect originates from the response of void finders to the distorted tracer field – which leads to reduction of the amplitude of the AP signal in the CCF – and thus depends on the specific void-finding algorithm used. We present results for four different void-finding packages, namely REVOLVER, VIDE, voxel, and the spherical void finder in the Pylians3 library, demonstrating how incorrect treatment of the AP effect results in biases in the recovered parameters, regardless of the technique used. Finally, we propose a method to alleviate this issue without resorting to complex and finder-specific modelling of the void-finder response to AP.
Auroral 3D structure retrieval from the Juno/UVS data
Authors: Benmahi B. , Bonfond B. , Benne B. , Hue V. , Grodent D. , Barthélemy M. , Sinclair J. A. , Moirano A. , Head L. A. , Gladstone R. , Gronoff G. , Sicorello G. , Simon Wedlund C. , Giles R. , Greathouse T. K.
Published: October 2024

Context. Jovian auroras, the most powerful in the Solar System, result from the interaction between the magnetosphere and atmosphere of Jupiter. While the horizontal morphology of these phenomena has been widely studied, their vertical structure, determined by the penetration depth of the magnetospheric electron into the auroral regions, remains relatively unexplored. Previous observations, including those from the Hubble Space Telescope (HST), have addressed this question to a limited extent.

Aims. In this study we aim to map the vertical structure of Jovian auroral emissions.

Methods. Using observations from Juno’s UltraViolet Spectrograph (UVS), we examined the vertical structure of the auroral emissions. Building on a recent study of auroral energy mapping based on UVS observations that mapped the average energy of precipitating electrons in the Jovian auroral regions, we find a relationship between this average energy and the volume emission rate (VER) of H2 for two types of electron energy distributions: monoenergetic and a kappa distribution with κ = 2.5.

Results. Using brightness maps, we derived the 3D VER structure of Jovian auroras in both northern and southern regions, across multiple spacecraft perijoves (PJs). By considering the example of PJ11, we find that the average altitude of the VER peak in the polar emission region is approximately ~250 km for the monoenergetic distribution case and ~190 km for kappa distribution case. In the main emission region, we find that the average altitude of the VER peak is approximately ~260 km for the case of monoenergetic distribution and ~197 km for kappa distribution case. For the other PJs, we obtained results that are very similar to those of PJ11.

Conclusions. Our findings are, on average, consistent with measurements from the Galileo probe and the HST observations. This study contributes to a better understanding of the complexity of Jovian auroras and highlights the importance of using Juno observations when probing their vertical structure. Considering the variability in the κ parameter in the auroral region, we also studied the impact of this variability on the vertical structure of the auroral emission. This sensitivity study reveals that the influence of the κ parameter on our results was very weak. However, the impact of the κ variability on the VER amplitude shows that there is an influence on the thermal structure and chemical composition of the atmosphere in the auroral regions.
The Effectiveness and Efficiency of Using E-Learning in a Digital Learning Environment
Authors: Othman Norfaridatul Akmaliah , Alamsyah Doni Purnama , Kerta Johan Muliadi , Morika Doni , Ramdhani Yudi
Published: October 2024

Human-Computer Interaction (HCI) supports the effectiveness and efficiency of using e-learning in a digital learning environment. Adapting technology to e-learning with the support of HCI is an important part of measuring e-learning effectiveness. This research aims to investigate how the implementation of HCI in digital learning affects the behavior of elearning users. The study was carried out by testing a model that can support e-learning effectiveness with the support of technological factors, pedagogical factors, individual characteristics and instructor characteristics. The survey research method was carried out by collecting data using quantitative methods. Data was obtained through online questionnaires from students with experience with e-learning environments. The data was tabulated and processed using a linear regression approach with the SmartPLS statistical data processing tool. Hypothesis were developed to test and analyze the research model. The research results show that technological factors, pedagogical factors, instructor characteristics, and individual characteristics of e-learning users can increase e-learning effectiveness. Individual characteristics are the main factors that can control e-learning effectiveness. The research findings explained the importance of interaction from e-learning users in measuring the success of implementing HCI in elearning. Universities, as providers of digital learning through e-learning, are deemed to pay attention to individual characteristics through face-to-face elearning designs that are more effective and user-friendly.
Test a 2D Physical Model of Seawall Stability at Various Slope Angles with A-Jack Armour Units
Authors: Sujantoko Sujantoko , Pangestu P.A. , Silva F.G.K. , Ahmad R.P. , Firman M.R.
Published: October 2024

Seawall designs must consider the type of armour unit, wave height, and economic factors. Selecting the appropriate size and type of protective unit can prevent excessive damage to structures at sea. In this study, the stability of the A-Jack armour unit was analyzed through physical model testing. Among the three structural slope variations in this test, AJack had the highest stability at a slope of 1:2. At a wave height of 0.1 m, the A-Jack was still not damaged, but the Tetrapod suffered damage of 0.43% and the BPPT-Lock of 0.83%. Antifer type 2 has a damage percentage of 2.3% with a stability number of 2.23, whereas A-Jack causes damage of 5.35% with a stability number of 2.26. As the stability coefficient decreases with increasing structural steepness, A-Jack has better stability than the Antifer.