bluuebunny/crossref_metadata_2025 huggingface dataset:
Proteomic analysis of cardiorespiratory fitness for prediction of mortality and multisystem disease risks
Authors: Perry Andrew S. , Farber-Eger Eric , Gonzales Tomas , Tanaka Toshiko , Robbins Jeremy M. , Murthy Venkatesh L. , Stolze Lindsey K. , Zhao Shilin , Huang Shi , Colangelo Laura A. , Deng Shuliang , Hou Lifang , Lloyd-Jones Donald M. , Walker Keenan A. , Ferrucci Luigi , Watts Eleanor L. , Barber Jacob L. , Rao Prashant , Mi Michael Y. , Gabriel Kelley Pettee , Hornikel Bjoern , Sidney Stephen , Houstis Nicholas , Lewis Gregory D. , Liu Gabrielle Y. , Thyagarajan Bharat , Khan Sadiya S. , Choi Bina , Washko George , Kalhan Ravi , Wareham Nick , Bouchard Claude , Sarzynski Mark A. , Gerszten Robert E. , Brage Soren , Wells Quinn S. , Nayor Matthew , Shah Ravi V.
Published: June 2024

Despite the wide effects of cardiorespiratory fitness (CRF) on metabolic, cardiovascular, pulmonary and neurological health, challenges in the feasibility and reproducibility of CRF measurements have impeded its use for clinical decision-making. Here we link proteomic profiles to CRF in 14,145 individuals across four international cohorts with diverse CRF ascertainment methods to establish, validate and characterize a proteomic CRF score. In a cohort of around 22,000 individuals in the UK Biobank, a proteomic CRF score was associated with a reduced risk of all-cause mortality (unadjusted hazard ratio 0.50 (95% confidence interval 0.48–0.52) per 1 s.d. increase). The proteomic CRF score was also associated with multisystem disease risk and provided risk reclassification and discrimination beyond clinical risk factors, as well as modulating high polygenic risk of certain diseases. Finally, we observed dynamicity of the proteomic CRF score in individuals who undertook a 20-week exercise training program and an association of the score with the degree of the effect of training on CRF, suggesting potential use of the score for personalization of exercise recommendations. These results indicate that population-based proteomics provides biologically relevant molecular readouts of CRF that are additive to genetic risk, potentially modifiable and clinically translatable.
Cognitive control training with domain-general response inhibition does not change children’s brains or behavior
Authors: Ganesan Keertana , Thompson Abigail , Smid Claire R. , Cañigueral Roser , Li Yongjing , Revill Grace , Puetz Vanessa , Bernhardt Boris C. , Dosenbach Nico U. F. , Kievit Rogier , Steinbeis Nikolaus
Published: June 2024

Cognitive control is required to organize thoughts and actions and is critical for the pursuit of long-term goals. Childhood cognitive control relates to other domains of cognitive functioning and predicts later-life success and well-being. In this study, we used a randomized controlled trial to test whether cognitive control can be improved through a pre-registered 8-week intervention in 235 children aged 6–13 years targeting response inhibition and whether this leads to changes in multiple behavioral and neural outcomes compared to a response speed training. We show long-lasting improvements of closely related measures of cognitive control at the 1-year follow-up; however, training had no impact on any behavioral outcomes (decision-making, academic achievement, mental health, fluid reasoning and creativity) or neural outcomes (task-dependent and intrinsic brain function and gray and white matter structure). Bayesian analyses provide strong evidence of absent training effects. We conclude that targeted training of response inhibition does little to change children’s brains or their behavior.
Sustainable conversion of polyethylene plastic bottles into terephthalic acid, synthesis of coated MIL-101 metal–organic framework and catalytic degradation of pollutant dyes
Authors: Zhou Fujiang , He Danfeng , Ren Guojian , Yarahmadi Hossein
Published: June 2024

Persistent environmental colored compounds, resistant to biodegradation, accumulate and harm eco-systems. Developing effective methods to break down these pollutants is crucial. This study introduces Ag-MIL-101 (Ag-MIL-101) as a composite and reusable catalyst that efficiently degrades specific colored organic pollutants (COPs) like Methylene blue (MB), 4-Nitrophenol (4-NP), and 4-Nitroaniline (4-NA) using sodium borohydride at room temperature. The MIL-101 was synthesized using Terephthalic acid (TPA) derived from the degradation of Polyethylene Terephthalate (PET) plastic waste, with the assistance of zinc chloride. To further investigation, the kinetics of degradation reaction was studied under optimized conditions in the presence of Ag-MIL-101 as catalyst. Our results demonstrated the remarkable efficiency of the degradation process, with over 93% degradation achieved within just 8 min. The catalyst was characterized using FTIR, XRD, FESEM, and TEM. In this study, the average particle size of Ag-MIL-101 was determined using SEM and XRD analysis. These methods allow us to accurately and precisely determine the particle size. We determined the reaction rate constants for the degradation of each COP using a pseudo first-order kinetic equation, with values of 0.585, 0.597 and 0.302 min−1 for MB, 4-NP, and 4-NA, respectively. We also evaluated the recyclability of the catalyst and found that it could be reused for up to three cycles with only a slight decrease in efficiency (10–15%). Overall, our findings highlight the promising application of Ag-MIL-101 as an effective catalyst for the degradation of COPs, emphasizing the importance of optimizing reaction conditions to achieve enhanced efficiency.
Dome versus single-cut osteotomies for correction of long bone deformities—technical considerations
Authors: Zindel Christoph , Hodel Sandro , Fürnstahl Philipp , Schweizer Andreas , Fucentese Sandro F. , Vlachopoulos Lazaros
Published: June 2024

Corrective osteotomy allows to improve joint loading, pain and function. In complex deformities, the biggest challenge is to define the optimal surgical solution, while considering anatomical, technical and biomechanical factors. While the single-cut osteotomy (SCOT) and focal dome osteotomy (FDO) are well-established treatment options, their mathematical relationship remain largely unclear. The aim of the study was (1) to describe the close mathematical relationship between the SCOT and FDO and (2) to analyze and introduce a novel technique—the stepped FDO—as a modification of the classic FDO. The mathematical background and relationship of SCOT and FDO are described for the example of a femoral deformity correction and visualized using a 3D surface model taking into account the benefits for the clinical application. The novel modifications of the stepped FDO are introduced and its technical and clinical feasibility demonstrated. Both, SCOT and FDO, rely on the same deformity axis that defines the rotation axis k for a 3D deformity correction. To achieve the desired correction using a SCOT, the resulting cutting plane is perpendicular to k, while using a FDO will result in a cylindrical cut with a central axis parallel to k. The SCOT and FDO demonstrate a strong mathematical relation, as both methods rely on the same deformity axis, however, resulting in different cutting planes. These characteristics enable a complementary use when defining the optimal type of osteotomy. This understanding enables a more versatile planning approach when considering factors as the surgical approach, biomechanical characteristics of fixation or soft tissue conditions. The newly introduced stepped FDO facilitates an exact reduction of the bone fragments and potentially expands the clinical applicability of the FDO.
Gut microbiome and inflammation among athletes in wheelchair in a crossover randomized pilot trial of probiotic and prebiotic interventions
Authors: Valido Ezra , Capossela Simona , Glisic Marija , Hertig-Godeschalk Anneke , Bertolo Alessandro , Stucki Gerold , Flueck Joelle Leonie , Stoyanov Jivko
Published: June 2024

Disorders related to gut health are a significant cause of morbidity among athletes in wheelchair. This pilot feasibility trial aims to investigate whether probiotics compared to prebiotics can improve inflammatory status and gut microbiome composition in elite athletes in wheelchair. We conducted a 12-week, randomized, cross-over controlled trial involving 14 elite Swiss athletes in wheelchair. Participants were given a multispecies-multistrain probiotic or prebiotic (oat bran) daily for 4 weeks (Clinical trials.gov NCT04659408 09/12/2020). This was followed by a 4-week washout and then crossed over. Thirty inflammatory markers were assessed using bead-based multiplex immunoassays (LegendPlex) from serum samples. The gut microbiome was characterized via 16S rRNA sequencing of stool DNA samples. Statistical analyses were conducted using linear mixed-effect models (LMM). At baseline, most athletes (10/14) exhibited low levels of inflammation which associated with higher gut microbiome alpha diversity indices compared to those with high inflammation levels. The use of probiotic had higher decrease in 25 (83%) inflammatory markers measured compared to prebiotic use. Probiotic has the potential in lowering inflammation status and improving the gut microbiome diversity. The future trial should focus on having sufficient sample sizes, population with higher inflammation status, longer intervention exposure and use of differential abundance analysis.
Tannic acid modified keratin/sodium alginate/carboxymethyl chitosan biocomposite hydrogels with good mechanical properties and swelling behavior
Authors: Zhu Liqing , Ouyang Fenfen , Fu Xue , Wang Yimei , Li Ting , Wen Min , Zha Guodong , Yang Xue
Published: June 2024

Natural polymer-based hydrogels have demonstrated great potential as wound-healing dressings. They help to maintain a moist wound environment as well as promote faster healing. In this work, a multifunctional hydrogel was prepared using keratin, sodium alginate, and carboxymethyl chitosan with tannic acid modification. Micro-morphology of hydrogels has been performed by scanning electron microscopy. Fourier Transform Infrared Spectroscopy reveals the presence of hydrogen bonding. The mechanical properties of the hydrogels were examined using a universal testing machine. Furthermore, we investigated several properties of the modified hydrogel. These properties include swelling rate, water retention, anti-freezing properties, antimicrobial and antioxidant properties, hemocompatibility evaluation and cell viability test in vitro. The modified hydrogel has a three-dimensional microporous structure, the swelling rate was 1541.7%, the elastic modulus was 589.74 kPa, the toughness was 211.74 kJ/m3, and the elongation at break was 75.39%, which was similar to the human skin modulus. The modified hydrogel also showed inhibition of S. aureus and E. coli, as well as a DPPH scavenging rate of 95%. In addition, the modified hydrogels have good biological characteristics. Based on these findings, the K/SA/CCS hydrogel holds promise for applications in biomedical engineering.
Effects of water flow and ocean acidification on oxygen and pH gradients in coral boundary layer
Authors: Martins Catarina P. P. , Ziegler Maren , Schubert Patrick , Wilke Thomas , Wall Marlene
Published: June 2024

Reef-building corals live in highly hydrodynamic environments, where water flow largely controls the complex chemical microenvironments surrounding them—the concentration boundary layer (CBL). The CBL may be key to alleviate ocean acidification (OA) effects on coral colonies by partially isolating them. However, OA effects on coral CBL remain poorly understood, particularly under different flow velocities. Here, we investigated these effects on the reef-building corals Acropora cytherea, Pocillopora verrucosa, and Porites cylindrica. We preconditioned corals to a control (pH 8.0) and OA (pH 7.8) treatment for four months and tested how low flow (2 cm s−1) and moderate flow (6 cm s−1) affected O2 and H+ CBL traits (thickness, surface concentrations, and flux) inside a unidirectional-flow chamber. We found that CBL traits differed between species and flow velocities. Under OA, traits remained generally stable across flows, except surface pH. In all species, the H+ CBL was thin and led to lower surface pH. Still, low flow thickened H+ CBLs and increased light elevation of surface pH. In general, our findings reveal a weak to null OA modulation of the CBL. Moreover, the OA-buffering capacity by the H+ CBL may be limited in coral species, though low flow could enhance CBL sheltering.
Extracellular fluid excess linked to reduced choroidal vascularity index in patients with chronic kidney disease
Authors: Kang Minjae , Oh Jongrok , Kim Min , Byeon Suk Ho , Kim Sung Soo , Shin Joo Youn
Published: June 2024

Extracellular fluid (ECF) excess is common in patients with chronic kidney disease (CKD). This study (involving 284 patients with CKD) explored the association between choroidal vascularity index (CVI) and ECF excess. We categorised patients into three groups based on extracellular water/total body water: normal, mildly overhydrated, and severely overhydrated. The more severe ECF status was associated with a lower CVI after adjustment (B = − 0.902, p = 0.001). In non-diabetic patients, both vascular luminal (LA, p < 0.001) and stromal areas (SA, p = 0.003) were significantly reduced in patients with severe ECF excess compared to others, whereas diabetic patients showed no significant differences in LA (p = 0.96) and SA (p = 0.86) based on ECF excess status. These findings suggest that ECF status may influence CVI in patients with CKD, underscoring the need for further research to clarify its direct impact on choroidal changes.
Cytological and molecular characterization of wheat lines carrying leaf rust and stem rust resistance genes Lr24 and Sr24
Authors: Li Jianbo , Guan Haixia , Wang Yuqi , Dong Chongmei , Trethowan Richard , McIntosh Robert A. , Zhang Peng
Published: June 2024

Previous studies showed that Australian wheat cultivars Janz and Sunco carry leaf rust and stem rust resistance genes Lr24 and Sr24 derived from Thinopyrum ponticum chromosome arm 3AgL. However, the size of the alien segments carrying Lr24 and Sr24 in the lines were not determined. In this study, we used non-denaturing fluorescence in situ hybridization (ND-FISH), genomic in situ hybridization (GISH), and PCR-based landmark unique gene (PLUG) markers to visualize the alien segments in Janz and Sunco, and further compared them with the segments in US cultivars Agent and Amigo. The fraction length (FL) of the alien translocation in Agent was 0.70–1.00, whereas those in Janz, Sunco, and Amigo were smaller, at FL 0.85–1.00. It was deduced that the alien gene RAg encoding for red grain color and rust resistance genes Lr24 and Sr24 on chromosome arm 3AgL were in bins of FL 0.70–0.85 and 0.85–1.00, respectively. We retrieved and extracted nucleotide-binding site-leucine-rich repeat (NBS-LRR) receptor genes corresponding to the region of Lr24 and Sr24 on chromosomes 3E, and 3J, 3Js and 3St from the reference genome sequences of Th. elongatum and Th. intermedium, respectively. A set of molecular markers developed for Lr24 and Sr24 from those extracted NBS-LRR genes will provide valuable information for fine mapping and cloning of these genes.
Use of a head-to-tail peptide cyclase to prepare hybrid RiPPs
Authors: Le Tung , Zhang Dongtianyu , Martini Rachel M. , Biswas Subhanip , van der Donk Wilfred A.
Published: June 2024

The biosynthetic enzymes that install the characteristic features of cyclotides and lanthipeptides were combined to make new-to-nature compounds.
Probing of nucleic acid compaction using low-frequency Raman spectroscopy
Authors: Sosorev Andrey Yu. , Parashchuk Olga D. , Chicherin Ivan V. , Trubitsyn Artem A. , Trukhanov Vasiliy A. , Baleva Maria V. , Piunova Ulyana E. , Kharlanov Oleg G. , Kamenski Piotr , Paraschuk Dmitry Yu.
Published: June 2024

In this study, we suggest an approach for probing the compaction of nucleic acids using low-frequency Raman spectroscopy.
Recent advances in nanomaterial-based solid-contact ion-selective electrodes
Authors: Mirabootalebi Seyed Oveis , Liu Yang
Published: June 2024

This review summarizes progress made over the past five years in the development of solid-contact ion-selective electrodes (SC-ISEs) based on nanomaterials, and provides insights into the prospects for this field.
A near-infrared fluorescent probe for imaging peroxynitrite levels in paw edema mice and drug evaluation
Authors: Hu Ling , Chen Si-Si , Zhang Hui , Chao Jing-Jing , Peng Zhen-Zhen , Mao Guo-Jiang , Hu Liufang , Ouyang Juan , Min Anjie , Li Chun-Yan
Published: June 2024

A near-infrared fluorescent probe (TX-P) for detecting peroxynitrite is constructed. The probe has long emission and large Stokes shift. TX-P can be used to visualize ONOO− in cells, image ONOO− in paw edema mice and evaluate anti-inflammatory drugs.
Strategic enzymatic enantioselective desymmetrization of prochiral cyclohexa-2,5-dienones
Authors: Kattula Bhavita , Munakala Anandarao , Kashyap Rajnandani , Nallamilli Tarun , Nagendla Narendra Kumar , Naza Surabhi , Mudiam Mohana Krishna Reddy , Chegondi Rambabu , Addlagatta Anthony
Published: June 2024

Asymmetric desymmetrization through the selective reduction of one double bond of prochiral 2,5-cyclohexadienones is highly challenging.
A universal and accurate LPMI method for calculating mismatch in heterogeneous ice nucleation
Authors: Deng Qiyuan , Wang Hong , Zhu Xun , Wu Junjun , Ding Yudong , Chen Rong , Liao Qiang
Published: June 2024

We propose an LPMI method to calculate the mismatch index heterogeneous ice nucleation. This new method is more physically sound as it considers both the lattice parameters and Miller index.
Characterization of adsorption sites on IrO2via temperature programmed O2 desorption simulations
Authors: Ocampo-Restrepo Vivianne K. , Vijay Sudarshan , Gunasooriya G. T. Kasun Kalhara , Nørskov Jens K.
Published: June 2024

We identify a new adsorption site related to the formation of steps on IrO2(110), that is essential for reproducing the experimental TPD.
Predicting spin states of iron porphyrins with DFT methods including crystal packing effects and thermodynamic corrections
Authors: Radoń Mariusz
Published: June 2024

Which DFT methods can most reliably predict the observed spin state in iron porphyrins with thermodynamics and crystal packing included?
The effects of alkyl substitution on the aggregation of π-conjugated dyes: spectroscopic study and modelling
Authors: Bardi Brunella , Sournia-Saquet Alix , Moreau Alain , Moineau-Chane Ching Kathleen I. , Terenziani Francesca
Published: June 2024

Mastering light emission: alkyl chains and mild stimuli make the difference.
Structural analysis of C8H6˙+ fragment ion from quinoline using ion-mobility spectrometry/mass spectrometry
Authors: Iwamoto Kenichi , Inoue Genki , Matsubara Hiroshi
Published: June 2024

The fragment ion structures of C8H6˙+ (m/z 102) from quinoline˙+(m/z 129) are analyzed using an ion-mobility spectrometer/mass spectrometer.
Vibrational circular dichroism spectra of proline in water at different pH values
Authors: Drost Deborah A. , Merten Christian
Published: June 2024

The computed VCD spectra of proline–water clusters depend on the orientation of the water molecules in the solvation shell. We thus use an MD-based solvent-shell approach to sample the configurational space of the solvent shell around the solute.
A mononuclear Fe(iii) complex showing thermally induced spin crossover and slow magnetic relaxation with reciprocating thermal behaviour
Authors: Bridová Terézia , Rajnák Cyril , Titiš Ján , Samoľová Erika , Tran Kevin , Malina Ondřéj , Bieńko Alina , Renz Franz , Gembický Milan , Boča Roman
Published: June 2024

AC susceptibility measurements of [FeIII(L5)(NCSe)] reveal a field supported slow magnetic relaxation with the sign of reciprocating thermal behaviour. The complex exhibits thermally induced spin crossover centred at T1/2 = 281 K.
Near-infrared afterglow enhancement of ZnGa2O4:Cr3+via regulating trap distribution guided by the VRBE diagram
Authors: Huang Shuyu , Han Xinxin , Zeng Chuanyu , Liang Anxian , Zou Bingsuo
Published: June 2024

The afterglow intensity and duration of ZnGa2O4:Cr3+ are enhanced by regulating its trap distribution through doping lanthanide (Ln = Sm, Yb, Tb) ions guided by the VRBE diagram. The afterglow enhancement mechanism is analyzed in detail.
Tuning sorbent properties to reduce the cost of direct air capture
Authors: Holmes Hannah E. , Banerjee Sayan , Vallace Anthony , Lively Ryan P. , Jones Christopher W. , Realff Matthew J.
Published: June 2024

A direct air capture (DAC) economic model that accounts for sorbent degradation is developed. Experimentally-measured parameters are then integrated to identify sorbent and process features that minimize both the DAC carbon footprint and cost.
Managing intermittency of renewable power in sustainable production of methanol, coupled with direct air capture
Authors: Fulham George J. , Mendoza-Moreno Paula V. , Marek Ewa J.
Published: June 2024

This study leverages worldwide wind data, process modelling, and life cycle assessment to reveal the potential of dynamic methanol production for atmospheric CO2 drawdown, while handling power intermittency and minimising reliance on reserve storage.
Light-assisted green and efficient construction of thiadiazole/selenadiazole derivatives
Authors: Wen Changting , Sun Guojin , Liu Lang , Zhang Jun , She Mengyao , Yang Zheng , Liu Ping , Zhang Shengyong , Li Jianli
Published: June 2024

A green and efficient one-pot photocatalytic synthetic methodology was presented for fabrication of thiadiazole/selenadiazole derivatives with good group tolerance, safe conditions, and high yields.
Site-specific thrombus formation: advancements in photothrombosis-on-a-chip technology
Authors: Liu Kuan-Ting , Wang Pai-Wen , Hsieh Han-Yun , Pan Han-Chi , Chin Hsian-Jean , Lin Che-Wei , Huang Yu-Jen , Liao Yung-Chieh , Tsai Ya-Chun , Liu Shang-Ru , Su I.-Chang , Song Yen-Fang , Yin Gung-Chian , Wu Kuang-Chong , Chuang Er-Yuan , Fan Yu-Jui (Ray) , Yu Jiashing
Published: June 2024

A photothrombosis-on-a-chip system with precise site-specific thrombus formation, controllable thrombus severity, and dual physiological environments for drug testing and thrombosis research.
From biomass to batteries: the contribution of silicon–carbon composites prepared from high-nitrogen egg whites and micron-sized silica powder to lithium-ion battery performance
Authors: Yang Pan , Mai Yi , Sun Ruida , Luo Mingjian , Dai Xinyi , Wu Fuzhong
Published: June 2024

This research uses egg white proteins as a carbon source to create silicon/nitrogen-doped composites, addressing silicon electrode volume expansion in lithium-ion batteries.
Synthesis of cyanoaminopyridyl enaminoates for their fluorescent “turn off” response towards Fe(iii) ions
Authors: Devi Lalita , Sasan Sonakshi , Changotra Avtar , Kapoor Kamal K.
Published: June 2024

In the present study, a series of 2-amino-3-cyanopyridine-based enaminoates 2 were synthesized from substituted 2-amino-3-cyanopyridines 3 and ethyl cyclopentanone-2-carboxylate 4 in acetic acid.
Exploration and modulation of the photophysical properties of bromelain in a bioamphiphilic micellar system: comparative studies on the basis of room temperature ionic liquids, anionic surfactants, drugs and salts
Authors: Dey Apensu , Chakraborty Sudipta , Ghosh Soumen
Published: June 2024

A new bioamphiphile sodium-2-decanamyde-2-methyl propanoate (SDMP) was synthesized to study the photophysical properties of bromelain (BM) in its micellar medium, and with the addition of RTILs, SDS, NaCl and NOT using spectroscopic methods.
Effect of indium addition on the electrocatalytic performance of Zn–Al–Inx hydroxide for CO2 reduction to CO
Authors: Sun Ting , Liu Tianxia , Ma Xuejiao , Zhang Yaping
Published: June 2024

The addition level of indium has a significant impact on the electrocatalytic performance of the catalysts. The Zn–Al–In0.2 hydroxide electrocatalyst CO FE prepared by hydrothermal synthesis can reach 97.56% at −1.1 V vs. RHE.
A determination of the Large Magellanic Cloud dark matter subhalo mass using the Milky Way halo stars in its gravitational wake
Authors: Fushimi K. J. , Mosquera M. E. , Dominguez M.
Published: June 2024

Aims. Our goal is to study the gravitational effects caused by the passage of the Large Magellanic Cloud (LMC) in its orbit on the stellar halo of the Milky Way.

Methods. We employed Gaia Data Release 3 to construct a halo tracers dataset consisting of K-giant stars and RR-Lyrae variables. Additionally, we compared the data with a theoretical model to estimate the dark matter subhalo mass.

Results. We have improved the characterisation of the local wake and the collective response due to the LMC’s orbit. We have also estimated for the first time the dark subhalo mass of the LMC to be of the order of 1.7 × 1011 M⊙, which is comparable to previously reported values in the literature.
Probing particle acceleration in Abell 2256: From 16 MHz to gamma rays
Authors: Osinga E. , van Weeren R. J. , Brunetti G. , Adam R. , Rajpurohit K. , Botteon A. , Callingham J. R. , Cuciti V. , de Gasperin F. , Miley G. K. , Röttgering H. J. A. , Shimwell T. W.
Published: June 2024

Merging galaxy clusters often host spectacular diffuse radio synchrotron sources. These sources can be explained by a non-thermal pool of relativistic electrons that are accelerated by shocks and turbulence in the intracluster medium. The origin of the pool and details of the cosmic ray transport and acceleration mechanisms in clusters are still open questions. Due to the often extremely steep spectral indices of diffuse radio emission, it is best studied at low frequencies. However, the lowest frequency window available to ground-based telescopes (10−30 MHz) has remained largely unexplored as radio frequency interference and calibration problems related to the ionosphere become severe. Here, we present LOFAR observations from 16 to 168 MHz targeting the famous cluster Abell 2256. In the deepest-ever images at decametre wavelengths, we detected and resolved the radio halo, radio shock, and various steep spectrum sources. We measured standard single power-law behaviour for the radio halo and radio shock spectra, with spectral indices of α = −1.56 ± 0.02 from 24 to 1500 MHz and α = −1.00 ± 0.02 from 24 to 3000 MHz, respectively. Additionally, we found significant spectral index and curvature fluctuations across the radio halo, indicating an inhomogeneous emitting volume. In contrast to the straight power-law spectra of the large-scale diffuse sources, the various AGN-related sources showed extreme steepening towards higher frequencies and flattening towards low frequencies. We also discovered a new fossil plasma source with a steep spectrum between 23 and 144 MHz, with α = −1.9 ± 0.1. Finally, by comparing radio and gamma-ray observations, we ruled out purely hadronic models for the radio halo origin in Abell 2256, unless the magnetic field strength in the cluster is exceptionally high, which is unsupportable by energetic arguments and inconsistent with the knowledge of other cluster magnetic fields.
Solar Jet Hunter: A citizen science initiative to identify and characterize coronal jets at 304 Å
Authors: Musset S. , Jol P. , Sankar R. , Alnahari S. , Kapsiak C. , Ostlund E. , Lasko K. , Glesener L. , Fortson L. , Fleishman G. D. , Panesar N. K. , Zhang Y. , Jeunon M. , Hurlburt N.
Published: June 2024

Context. Solar coronal jets seen in extreme ultraviolet (EUV) are ubiquitous on the Sun, and they have been found in and at the edges of active regions, at the boundaries of coronal holes, and in the quiet Sun. Jets have various shapes, sizes, brightness, velocities, and durations in time, which complicates their detection by automated algorithms. So far, solar jets reported in the Heliophysics Event Knowledgebase (HEK) have been mostly reported by humans looking for them in the data, with different levels of precision regarding their timing and positions.

Aims. We created a catalog of solar jets observed in EUV at 304 Å containing precise and consistent information on the jet timing, position, and extent.

Methods. We designed a citizen science project, Solar Jet Hunter, on the Zooniverse platform, to analyze EUV observations at 304 Å from the Solar Dynamic Observatory/Atmospheric Imaging Assembly (SDO/AIA). We created movie strips for regions of the Sun in which jets have been reported in HEK and ask the volunteers to 1) confirm the presence of at least one jet in the data and 2) report the timing, position, and extent of the jet.

Results. We report here the design of the project and the results obtained after the analysis of data from 2011 to 2016. We note that 365 “coronal jet” events from HEK served as input for the citizen science project, equivalent to more than 120 000 images distributed into 9689 “movie strips”. Classification by the citizen scientists resulted in 883 individual jets being identified.

Conclusions. We demonstrate how citizen science can enhance the analysis of solar data with the example of Solar Jet Hunter. The catalog of jets thusly created is publicly available and will enable statistical studies of jets and related phenomena. This catalog will also be used as a training set for machines to learn to recognize jets in further datasets.
Spectral characterisation of the extinction properties of NGC 3603 using JWST NIRSpec
Authors: Rogers Ciarán , Brandl Bernhard , De Marchi Guido
Published: June 2024

Context. A necessary ingredient in understanding the star formation history of a young cluster is knowledge of the extinction towards the region. This has typically been done by making use of the colour-difference method with photometry, or similar methods utilising the colour-colour diagram. These approaches rely on adopting an extinction law with a given total-to-selective extinction ratio R(V), or determining a value of R(V) through empirical relationships. They also rely upon accurate spectral classification, reliable stellar isochrones, and separating field stars from genuine cluster members.

Aims. The colour excess E(B − V) can be independently determined by studying the decrements of the recombination lines produced by the nebular gas. Having access to many recombination lines from the same spectral series removes the need of adopting an extinction curve. Rather, different extinction curves can be trialled and the most appropriate one selected based on a minimum χ2 procedure.

Methods. Using the Micro-Shutter Assembly (MSA) on board the Near InfraRed Spectrograph (NIRSpec), multi-object spectroscopy was performed, yielding 600 nebular spectra from the Galactic massive star formation region NGC 3603. The recombination line intensity ratios were used to determine independent values of E(B − V). A series of extinction curves were trialled ranging from R(V) = 2 to R(V) = 8. The appropriate value of R(V) was adopted based on the minimum χ2 procedure.

Results. The extinction characteristics of NGC 3603 are similar to other Galactic HII regions like Orion, as well as starburst regions such 30 Doradus in the Large Magellanic Cloud, in that we find a relatively large value of R(V) = 4.8 ± 1.06, larger than the Galactic average of 3.1. We find a typical value of E(B − V) = 0.64 ± 0.27, significantly lower than values determined in previous studies. We also present a stacked nebular spectrum with a typical continuum signal-to-noise (S/N) = 70. This spectrum highlights the recombination lines of the HII region, several s-process elements such as Kr III and Se IV, and molecular H2 emission lines. This high S/N spectrum can act as a helpful template for identifying nebular emission lines.

Conclusions. Using ratios of hydrogen recombination lines, we calculated the value of R(V), E(B − V) and A(V) for > 200 lines of sight across NGC 3603. An extinction curve with a typical value R(V) = 4.8 ± 1.06 is required to explain the colour excess observed in the nebular spectra. This corresponds to a typical E(B − V) = 0.64 ± 0.27. This is significantly lower than what has been found in previous extinction studies of NGC 3603.
Kelvin-Helmholtz instability and heating in oscillating loops perturbed by power-law transverse wave drivers
Authors: Karampelas Konstantinos , Van Doorsselaere Tom , Guo Mingzhe , Duckenfield Timothy , Pelouze Gabriel
Published: June 2024

Context. Instabilities in oscillating loops are believed to be essential for dissipating the wave energy and heating the solar coronal plasma.

Aims. Our aim is to study the development of the Kelvin-Helmholtz (KH) instability in an oscillating loop that is driven by random footpoint motions.

Methods. Using the PLUTO code, we performed 3D simulations of a straight gravitationally stratified flux tube. The loop footpoints are embedded in chromospheric plasma, in the presence of thermal conduction and an artificially broadened transition region. Using drivers with a power-law spectrum, one with a red noise spectrum and one with the low-frequency part subtracted, we excited standing oscillations and the KH instability in our loops, after one-and-a-half periods of the oscillation.

Results. We see that our broadband drivers lead to fully deformed, turbulent loop cross-sections over the entire coronal part of the loop due to the spatially extended KH instability. The low RMS velocity of our driver without the low-frequency components supports the working hypothesis that the KH instability can easily manifest in oscillating coronal loops. We report for the first time in driven transverse oscillations of loops the apparent propagation of density perturbations due to the onset of the KH instability, from the apex towards the footpoints. Both drivers input sufficient energy to drive enthalpy and mass flux fluctuations along the loop, while also causing heating near the driven footpoint of the oscillating loop, which becomes more prominent when a low-frequency component is included in the velocity driver. Finally, our power-law driver with the low-frequency component provides a RMS input Poynting flux of the same order as the radiative losses of the quiet-Sun corona, giving us promising prospects for the contribution of decayless oscillations in coronal heating.
The CARMENES search for exoplanets around M dwarfs
Authors: von Stauffenberg A. , Trifonov T. , Quirrenbach A. , Reffert S. , Kaminski A. , Dreizler S. , Ribas I. , Reiners A. , Kürster M. , Twicken J. D. , Rapetti D. , Caballero J. A. , Amado P. J. , Béjar V. J. S. , Cifuentes C. , Góngora S. , Hatzes A. P. , Henning Th. , Montes D. , Morales J. C. , Schweitzer A.
Published: June 2024

Context. GJ 581 is a nearby M dwarf known to host a packed multiple planet system composed of two super-Earths and a Neptune-mass planet. We present new orbital analyses of the GJ 581 system, utilizing recent radial velocity (RV) data obtained from the CARMENES spectrograph combined with newly reprocessed archival data from the HARPS and HIRES spectrographs.

Aims. Our aim was to analyze the post-discovery spectroscopic data of GJ581, which were obtained with CARMENES. In addition, we used publicly available HIRES and HARPS spectroscopic data to seek evidence of the known and disputed exoplanets in this system. We aimed to investigate the stellar activity of GJ 581 and update the planetary system’s orbital parameters using state-of-the-art numerical models and techniques.

Methods. We performed a periodogram analysis of the available precise CARMENES, HIRES, and HARPS RVs and of stellar activity indicators. We conducted detailed orbital analyses by testing various orbital configurations consistent with the RV data. We studied the posterior probability distribution of the parameters fit to the data and we explored the long-term stability and overall orbital dynamics of the GJ 581 system.

Results. We refined the orbital parameters of the GJ 581 system using the most precise and complete set of Doppler data available. Consistent with the existing literature, our analysis confirms that the system is unequivocally composed of only three planets detectable in the present data, dismissing the putative planet GJ 581 d as an artifact of stellar activity. Our N-body fit reveals that the system’s inclination is i = 47.0−13.0+14.6 deg, which implies that the planets could be up to 30% more massive than their previously reported minimum masses. Furthermore, we report that the GJ 581 system exhibits long-term stability, as indicated by the posterior probability distribution, characterized by secular dynamical interactions without the involvement of mean motion resonances.
Deriving physical parameters of unresolved star clusters
Authors: Daugevičius Karolis , Kriščiūnas Eimantas , Cicėnas Erikas , Stonkutė Rima , Vansevičius Vladas
Published: June 2024

Context.Recently, it has been noticed that the discrepancies in the integrated colour indices (CIs) between star clusters and models are mostly due to the projection of bright stars in the apertures. In order to reduce this problem, the method of adaptive aperture photometry has been proposed. This method has been applied to star clusters from theM 31PanchromaticHubbleAndromeda Treasury (PHAT) survey, and studies show that the adaptive aperture photometry performs better than the conventional approach.

Aims.The aim of this study is to determine the best achievable limits on the accuracy and applicability of the aperture photometry method for studying star clusters in the local Universe.

Methods.We computed a large network of artificial 3D star clusters spanning the parameter space of theM 31clusters. We then simulated images of these clusters by projecting each onto a 2D plane from 100 directions. Star cluster images were generated in six passbands to match the PHAT survey. To investigate the limiting accuracy of aperture photometry and the limits of its applicability to star cluster studies, we measured the simulated images and performed parameter determination tests.

Results.We demonstrate that star clusters with and without post-main-sequence stars have significant photometric differences. We show that in order to obtain reliable physical parameters of star clusters, the CIs must be measured using an aperture with a radius larger than the cluster’s half-light radius. Furthermore, we demonstrate that the parameter determination of young clusters (∼10 Myr) is problematic regardless of the aperture size used. Therefore, it is advisable to determine the parameters of these clusters using colour-magnitude diagram fitting methods, when possible. We also show that the randomness of the viewing angle can lead to a CI uncertainty of up to 0.1 mag, depending on cluster parameters and aperture size.
Barium stars as tracers of s-process nucleosynthesis in AGB stars
Authors: Világos B. , Cseh B. , Yagüe López A. , Joyce M. , Karakas A. , Tagliente G. , Lugaro M.
Published: June 2024

Context. Barium (Ba) stars help to verify asymptotic giant branch (AGB) star nucleosynthesis models since they experienced pollution from an AGB binary companion and thus their spectra carry the signatures of the slow neutron capture process (s process).

Aims. For a large number (180) of Ba stars, we searched for AGB stellar models that match the observed abundance patterns. We aim to uncover any systematic deviations of the sample abundances from the predictions of the nucleosynthesis models.

Methods. We employed three machine learning algorithms as classifiers: a Random Forest method, developed for this work, and the two classifiers used in our previous study. Compared to that work, we also expanded our observational sample with 11 Ba stars available in the supersolar metallicity range. We studied the statistical behaviour of the different s-process elements in the observational sample to investigate if the AGB models systematically under- or overpredict the abundances observed in the Ba stars and show the results in the form of violin plots of the residuals between spectroscopic abundances and model predictions. We inspected the correlations between the observed [Fe/H], the s-process elemental abundances, and the residuals. We employed the [Zr/Fe] and [Nb/Fe] abundances as a thermometer to constrain the operational temperature that rules the production of these elements in the sample stars, assuming a steady-state s process. We also investigated the mass distribution of the identified polluter AGB stars and the behaviour of the δ parameter, which describes the fraction of accreted AGB material relative to the Ba star envelope.

Results. We find a significant trend in the residuals that implies an underproduction of the elements just after the first s-process peak (Nb, Mo, and Ru) in the models relative to the observations. This may originate from a neutron-capture process (e.g. the intermediate neutron-capture process, i process) not yet included in the AGB models of metallicity from solar to roughly 1/5 solar, corresponding to the range of the Ba stars. Correlations are found between the residuals of these peculiar elements, suggesting a common origin for the deviations from the models. In addition, there is a weak metallicity dependence of the residuals of these elements. The s-process temperatures derived with the [Zr/Fe] – [Nb/Fe] thermometer have an unrealistic value for the majority of our stars. The most likely explanation is that at least a fraction of these elements are not produced in a steady-state s process, and instead may be due to processes not included in the AGB models. The mass distribution of the identified models confirms that our sample of Ba stars was polluted by low-mass AGB stars (< 4 M⊙). Most of the matching AGB models require low accreted mass, but a few systems with high accreted mass are needed to explain the observations.
Gamma-ray line emission from the Local Bubble
Authors: Siegert Thomas , Schulreich Michael M. , Bauer Niklas , Reinhardt Rudi , Mittal Saurabh , Yoneda Hiroki
Published: June 2024

Deep-sea archives that include intermediate-lived radioactive60Fe particles suggest the occurrence of several recent supernovae inside the present-day volume of the Local Bubble during the last ~10 Myr. The isotope60Fe is mainly produced in massive stars and ejected in supernova explosions, which should always result in a sizeable yield of26Al from the same objects.60Fe and26Al decay with lifetimes of 3.82 and 1.05 Myr, and emitγrays at 1332 and 1809 keV, respectively. Theseγrays have been measured as diffuse glow of the Milky Way, and would also be expected from inside the Local Bubble as foreground emission. Based on two scenarios, one employing a geometrical model and the other state-of-the-art hydrodynamics simulations, we estimated the expected fluxes of the 1332 and 1809 keVγ-ray lines, as well as the resulting 511 keV line from positron annihilation due to the26Alβ+decay. We find fluxes in the range of 10−6–10−5ph cm−2s−1for all three lines with isotropic contributions of 10–50%. We show that these fluxes are within reach for the upcoming COSI-SMEXγ-ray telescope over its nominal satellite mission duration of 2 yr. Given the Local Bubble models considered, we conclude that in the case of 10–20 Myr-old superbubbles, the distributions of60Fe and26Al are not co-spatial - an assumption usually made inγ-ray data analyses. In fact, this should be taken into account however when analysing individual nearby targets for their60Fe to26Al flux ratio as this gauges the stellar evolution models and the age of the superbubbles. A flux ratio measured for the Local Bubble could further constrain models of60Fe deposition on Earth and its moon.
Stackelberg exact controllability of a class of nonlocal parabolic equations
Authors: Djomegne Landry , Kenne Cyrille
Published: June 2024

This paper deals with a multi-objective control problem for a class of nonlocal parabolic equations, where the non-locality is expressed through an integral kernel. We present the Stackelberg strategy that combines the concepts of controllability to trajectories with optimal control. The strategy involves two controls: a main control (the leader) and a secondary control (the follower). The leader solves a controllability to trajectories problem which consists to drive the state of the system to a prescribed target at a final time while the follower solves an optimal control problem which consists to minimize a given cost functional. The paper considers two cases: in the first case, both the leader and the follower act in the interior of the domain, and in the second case, the leader acts in the interior of the domain and the follower acts on a small part of the boundary. These results are applied to both linear and nonlinear nonlocal parabolic systems.
Improved cotton fences for a sustainable approach to cotton cleaning
Authors: Tashpulatov Dilshod , Tashpulatov Salikh , Tyurin Igor , Norboeva Ranokhon , Ismailov Alisher
Published: June 2024

The article presents the results of research on the improvement of the grate to improve the efficiency of cleaning cotton gins from major contaminants. To achieve the goals of increasing efficiency, the existing technologies for cleaning raw cotton and the equipment used were analyzed. In the studies, industrial varieties of raw cotton, the most common in the region, were chosen as raw materials. Cotton I-technical grade was used with a soiling level of 6.6% and a moisture content of 8.2%. By attaching the cotton wool to the saw drum, one can increase the distance between the posts by increasing the distance between the strings by moving the first post down a distance L to make sure it also goes to the lower drum of the saw in the access path. In the experiments, the distance between the first column and the second column was set equal to 40 mm, 50 mm, 60 mm and 70 mm, and the distribution of sawdust in the drums was studied taking into account the amount of cotton transported. The main attention during the experimental studies was directed to the location of the grates relative to the saw cylinder and the distance between the grates. For experimental studies, laboratory equipment was manufactured and carried out in the conditions of the Joint-Stock Company “Scientific Center of the Cotton Industry”. As a result, with the improvement of the location of the grate on the grate, the cleaning efficiency was 42.6%, and the number of pieces of cotton in the waste was 5.2%, as indicated in the technological description of the unit, the number of grates increased by one unit.
Study of the structure of fibrous composite material using computational x-ray tomography
Authors: Artemiev Andrey , Reznichenko Vyacheslav , Yurgenson Sergey , Pashkov Aleksey
Published: June 2024

the article discusses the determination of the actual porosity and the actual volumetric content of the reinforcing material and binder in a sample of fibrous polymer composite material (FPCM) using the non-destructive method of computational x-ray tomography. It is shown that the linear attenuation coefficient (LAC) of X-ray radiation in the volume of the sample under study based on the set of integral shadow projections obtained by X-ray transmission in various directions and its root-mean-square deviation (RMSD) provide sufficient information about the parameters of the microstructure of the sample under study. To obtain quantitative characteristics of porosity and volumetric content of components, it is necessary to examine test samples made from similar components with previously known various parameters of the material structure in the required range of scatter of these characteristics. The proposed method can be used as a non-destructive control of the structure parameters of critically important products made of VPCM, both in general and in selected local areas of the product. Also, this method is recommended for determining the actual porosity and the actual volumetric content of the binder when carrying out research work on the influence of VPCM structure parameters on the durability and residual strength of samples when exposed to external factors during operation, in particular when carrying out certification work on elementary samples.