bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gargantuan chaotic gravitational three-body systems II. Dependence on angular momentum and astrophysical scale
Authors: Boekholt T C N , Portegies Zwart S F 
Published: December 2024

ABSTRACT
Recently, we estimated that about 5 per cent of unstable supermassive black hole triple systems are fundamentally unpredictable. These gargantuan chaotic systems are able to exponentially magnify Planck length perturbations to astronomical scales within their dynamical lifetime. These results were obtained in the zero angular momentum limit, which we naively expected to be the most chaotic. Here, we generalize to weakly and non-hierarchical triple systems with a range of non-zero angular momenta by systematically varying the initial virial ratio. We find the surprising result that increasing the angular momentum enhances their ability to amplify small perturbations, which we tracked up to 90 orders of magnitude using the arbitrary-precision N-body code brutus. This result is partially explained by the fact that triples with higher angular momenta have longer lifetimes, allowing for a prolonged exponential growth. However, we also find that for a fixed lifetime, triples with higher angular momenta can amplify perturbations to larger values, indicating that the Lyapunov exponent is also a function of angular momentum. These empirical results provide targets for three-body theories which invoke chaos drivers such as resonance overlap and punctuated chaos. Comparing the zero angular momentum case to our new ensembles with higher angular momenta, we conclude that the percentage of unpredictable supermassive black hole triples increases up to about 30 per cent. A further increase up to about 50 per cent is reached when considering triples on smaller astrophysical scales. Fundamental unpredictability is thus a generic feature of chaotic, self-gravitating triple populations.
Panning for gold with the Neil Gehrels Swift Observatory: an optimal strategy for finding the counterparts to gravitational wave events
Authors: Eyles-Ferris R A J , Evans P A , Breeveld A A , Cenko S B , Dichiara S , Kennea J A , Klingler N J , Kuin N P M , Marshall F E , Oates S R , Page M J , Raman G , Ronchini S , Siegel M H , Tohuvavohu A , Campana S , D’Elia V , Hartmann D H , Osborne J P , Page K L , De Pasquale M , Troja E 
Published: December 2024

ABSTRACT
The LIGO, Virgo, and KAGRA (LVK) gravitational wave observatories are currently undertaking their O4 observing run offering the opportunity to discover new electromagnetic counterparts to gravitational wave events. We examine the capability of the Neil Gehrels Swift Observatory (Swift) to respond to these triggers, primarily binary neutron star mergers, with both the UV/Optical Telescope (UVOT) and the X-ray Telescope (XRT). We simulate Swift’s response to a trigger under different strategies using model skymaps, convolving these with the 2MPZ catalogue to produce an ordered list of observing fields, deriving the time taken for Swift to reach the correct field and simulating the instrumental responses to modelled kilonovae and short gamma-ray burst afterglows. We find that UVOT, using the u filter with an exposure time of order 120 s, is optimal for most follow-up observations and that we are likely to detect counterparts in $\sim 6$ per cent of all binary neutron star triggers detectable by LVK in O4. We find that the gravitational wave 90 per cent error area and measured distance to the trigger allow us to select optimal triggers to follow-up. Focussing on sources less than 300 Mpc away, or 500 Mpc if the error area is less than a few hundred square degrees, distances greater than previously assumed, offer the best opportunity for discovery by Swift with $\sim 5\!-\!30$ per cent of triggers having detection probabilities $\ge 0.5$. At even greater distances, we can further optimise our follow-up by adopting a longer 250 s or 500 s exposure time.
Discontinuous Galerkin method with constrained transport for modelling solar wind in spherical coordinates
Authors: Zhang Man , Feng Xueshang , Li Caixia , Yang Liping , Zhou Yufen , Liu Xiaojing , Bai Yujuan 
Published: December 2024

ABSTRACT
In this paper, the discontinuous Galerkin (DG) method is used to simulate the steady-state solar wind with constrained transport method. A cell-based piecewise quadratic polynomial solution is obtained through the DG scheme, while the face-averaged magnetic field is discretized using constrained-transport method. Then, a globally divergence-free magnetic field is constructed by combining the quadratic polynomial of magnetic field with the face-averaged magnetic field. For the time discretization, third-order Runge–Kutta method is applied. The resulting method can reach three order of accuracy in space and time. We test the method by computing the solar wind in Carrington rotation 2234, and compare the result with both remote sensing observations from SOHO and SDO as well as in situ observations from Parker Solar Probe and a dataset of Open to the Maximum Number of Investigators (OMNI). The agreement between the modelled results and the observations demonstrates the capability of the developed scheme.
Quantifying spectroscopic Ca ii exocomet transit occurrence in two decades of HARPS data
Authors: Bendahan-West Raphaël , Kennedy Grant M , Brown David J A , Strøm Paul A 
Published: December 2024

ABSTRACT
The field of exocomets has been built around the unmatched number of detections made in the circumstellar disc of the archetypal star Beta Pictoris. An exocomet detection in spectroscopy is identified by variable atomic absorption features in a stellar spectrum, associated with transiting gas in and trailing an exocomet coma. This paper presents the largest spectroscopic search for exocomet transits to date, which overcomes the limitations of biased samples of stars with debris discs, and instead looks through the ${\approx} 7500$ stars in the High Accuracy Radial velocity Planet Searcher (HARPS) archive for signs of exocomets in the Ca ii doublet (H: 396.847 nm and K: 393.366 nm). The search resulted in 155 candidate stars, which after filtering for false positives (e.g. binaries, stellar activity, etc.) were cut down to 22 stars. These 22 stars are classified into Tier 1, Tier 2, and Tier 3 exocomet candidates, reflecting the confidence level of their exocomet detection. Our two best candidates (Tier 1: Beta Pictoris and HD 172555) and four lower confidence candidates (Tier 2: Gl 1, HIP 5158, HD 94771, and HR 1996) are discussed, yielding a detection rate of 0.03 per cent (Tier 1 only) and 0.1 per cent (Tier 1 and Tier 2) in the HARPS sample. Both Tier 1 stars are known exocomet host stars. These two young A-type stars correspond to 0.4 per cent of all A-types in the sample, suggesting that detecting signs of exocomet transits using Ca ii is more likely around young A-type stars. Reanalysing a past HARPS study, we found no evidence to support the previously claimed four exocomet detections, indicating either that those detections are not robust or that we are only sensitive to the strongest signals.
Navigating a Fine Balance: Point-Mutant Cheater Viruses Disrupt the Viral Replication Cycle
Authors: Meir Moran , Kahn Arielle , Farage Carmel , Maoz Yael , Harel Noam , Ben Zvi Adi , Segev Shir , Volkov Maria , Yahud Ravit , Gophna Uri , Stern Adi 
Published: December 2024

Abstract
Cheater viruses cannot replicate on their own yet replicate faster than the wild type (WT) when the 2 viruses coinfect the same cell. Cheaters must possess dual genetic features: a defect, which leads to their inability to infect cells on their own, and a selective advantage over WT during coinfection. Previously, we have discovered 2 point-mutant cheaters of the MS2 bacteriophage. Here, we set out to discover the possible repertoire of cheater MS2 viruses by performing experimental evolution at a very high multiplicity of infection. Our results revealed a third point-mutant cheater that arose in 8 biological replicas. Each of the 3 primary cheaters disrupts the fine balance necessary for phage replication, in different ways that create a defect + advantage. We found that over time, the point-mutant cheaters accumulate additional secondary mutations, which alter other stages of the viral replication cycle, complementing the disruptions created by the original cheater. Intriguingly, cheater and secondary mutations almost always reside in very close proximity on the genome. This region encodes for multiple functions: overlapping reading frames as well as overlapping RNA structures critical for transitioning from one stage to another in the viral replication cycle. This region of overlap explains the dual functions of cheaters, as one mutation can have pleiotropic effects. Overall, these findings underscore how viruses, whose dense genomes often have overlapping functions, can easily evolve point-mutant cheaters, and how cheaters can evolve to alter the intricate balance of the viral replication cycle.
The Staphylococcus aureus non-coding RNA IsrR regulates TCA cycle activity and virulence
Authors: Rios-Delgado Gustavo , McReynolds Aubrey K G , Pagella Emma A , Norambuena Javiera , Briaud Paul , Zheng Vincent , Munneke Matthew J , Kim Jisun , Racine Hugo , Carroll Ronan K , Zelzion Ehud , Skaar Eric , Bose Jeffrey L , Parker Dane , Lalaouna David , Boyd Jeffrey M 
Published: December 2024

Abstract
Staphylococcus aureus has evolved mechanisms to cope with low iron (Fe) availability in host tissues. Staphylococcus aureus uses the ferric uptake transcriptional regulator (Fur) to sense titers of cytosolic Fe. Upon Fe depletion, apo-Fur relieves transcriptional repression of genes utilized for Fe uptake. We demonstrate that an S. aureus Δfur mutant has decreased expression of acnA, which codes for the Fe-dependent enzyme aconitase. This prevents the Δfur mutant from growing with amino acids as sole carbon and energy sources. We used a suppressor screen to exploit this phenotype and determined that a mutation that decreases the transcription of isrR, which produces a regulatory RNA, increased acnA expression, thereby enabling growth. Directed mutation of bases predicted to facilitate the interaction between the acnA transcript and IsrR, decreased the ability of IsrR to control acnA expression in vivo and IsrR bound to the acnA transcript in vitro. IsrR also bound transcripts coding the alternate tricarboxylic acid cycle proteins sdhC, mqo, citZ and citM. Whole-cell metal analyses suggest that IsrR promotes Fe uptake and increases intracellular Fe not ligated by macromolecules. Lastly, we determined that Fur and IsrR promote infection using murine skin and acute pneumonia models.
Mechanistic insights into the formation of hydroxides with unconventional coordination environments to achieve their cost-effective synthesis
Authors: Chen Zongkun , Fan Qiqi , Wang Xingkun , Kang Liqun , Wan Wenchao , Avaro Jonathan Thomas , Zhang Siyuan , Scheu Christina , Zhou Jian , DeBeer Serena , Heumann Saskia , Huang Minghua , Jiang Heqing , Cölfen Helmut 
Published: December 2024

ABSTRACT
Transition metal hydroxides, comprising metal-centered polyhedra, are abundant in nature and have a broad range of applications. Although the intercalation/deintercalation of polyhedra with unconventional coordination numbers (UCN) plays a pivotal role in their formation process and influences their chemical behavior, the detailed mechanism remains obscure. Here, taking the kinetically controlled growth of Co(OH)2 as a model system (where polyhedra with UCN refers to 4-coordinated tetrahedra), by combining in situ pH measurement and in situ ultraviolet–visible (UV–vis) spectroscopy, we tracked Co2+ tetrahedral intercalation/deintercalation with varying OH− concentrations, discovering that the initial Co2+ tetrahedral intercalation into the Co(OH)2 lattice is inevitable and its retention is influenced by the effective OH− concentration, challenging previous beliefs about the formation of Co(OH)2 and potentially other hydroxides. More importantly, an understanding of the intercalation mechanism would significantly contribute to optimization of the synthesis conditions of hydroxides with tunable coordination environments, which hold significant application potential, as evidenced by a proof-of-concept application in the oxygen evolution reaction.
Electronic-Cigarette and Heated Tobacco Product Use in the United Arab Emirates, an Emerging EC and HTP Market: A Cross-Sectional Analysis of the International Tobacco Control UAE Survey
Authors: Leinberger-Jabari Andrea , Ahmad Amar , Lindson Nicola , Oke Jason , Hartmann-Boyce Jamie , Fong Geoffrey T , El-Shahawy Omar , Ali Raghib , Sherman Scott E 
Published: December 2024

Abstract

Introduction
Electronic cigarettes (ECs) and heated tobacco products (HTPs) are recent arrivals to the nicotine product market in the Middle East, which are rapidly growing in popularity in the region. There is a lack of surveillance data at the country-level on use of these products and factors associated with their use.

Aims and Methods
This study analyzed a subset of data from the United Arab Emirates Healthy Future Study, a population-based cohort study of the Emirati population, to determine the factors associated with EC and HTP use among a sample of Emirati adults (≥18 years). The baseline assessment and supplementary questionnaires, conducted from 2016 to 2023, included data on combustible tobacco use, EC, and HTP use and sociodemographic characteristics.

Results
Of the 2041 individuals who answered questions on EC use, 32% reported ever using them. Of the 521 people who provided data on HTP, 30% reported ever using them. After adjusting for age, sex, education, perceived harms, and perceived addictiveness of EC, current EC use was associated with baseline combustible tobacco smoking (aOR = 27.63, 95% confidence interval [CI] 14.39, 53.06), users of a younger age (aOR = 0.91, 95% CI = 0.88, 0.95), and users of male sex (OR = 2.15, 95% CI = 1.21, 3.81). Current HTP use was less common but was also associated with baseline combustible tobacco use.

Conclusions
The use of ECs and HTPs was more common among those who used combustible tobacco. Future research should examine use trajectories among those who do and do not smoke, as well as the uptake of these products among youth.

Implications
Non-combustible nicotine products are growing in popularity in the Middle East Region. Our study found that EC and HTP use is associated with baseline combustible tobacco use and that concurrent users may use them to cut down on their combustible tobacco use. Continued comprehensive population-based monitoring of all-tobacco and nicotine products, especially EC and HTP use, will provide current data to aid in appropriately informing public health and harm reduction messages and programming
Supporting patients with advanced cancer and their spouses in parenting minor children: results of a randomized controlled trial
Authors: Milbury Kathrin , Ann-Yi Sujin , Whisenant Meagan S , Jones Morgan , Li Yisheng , Necroto Victoria , Yousuf Sania D , Chavez-MacGregor Mariana , Meyers Larrisa , Bruera Eduardo 
Published: December 2024

Abstract

Introduction
Patients with advanced cancer and their spousal caregivers who parent minor children report unmet parenting concerns and increased psychological distress. Seeking to address these important supportive care needs, this RCT examined the feasibility, acceptability, and initial evidence for the efficacy of a novel psychosocial intervention.

Patients and Methods
Patients with a metastatic solid malignancy and their spouses completed self-reported validated assessments of psychological symptoms and cancer-related parenting outcomes and were then randomized to the parent support intervention or a usual care (UC) group. Both groups were reassessed 6 and 12 weeks later. Dyads randomized to the counselor-led intervention attended the first 2 sessions jointly addressing illness communication and family routines. Spouses individually attended the last 2 sessions focusing on caregiver support and family death preparedness.

Results
Fifty patients and their spouses were randomized. All a priori feasibility benchmarks were met. Attendance in the intervention arm was high with 84% of caregivers attending all 4 sessions (mean = 3.48). The program was evaluated favorably by all patients and spouses deeming the intervention as beneficial. Caregivers rated the individual-level sessions as particularly helpful. Multilevel analyses revealed a significant reduction in anxiety symptoms (P = .05) and improvement in parenting efficacy (P = .03) at 6-week follow-up in the intervention group compared with UC.

Conclusions
The initial testing of our parent support intervention yielded promising results regarding feasibility and preliminary evidence for efficacy for reduced anxiety symptoms and improved parenting efficacy. This program may meet a frequent and distressing psychosocial need that is typically unaddressed by multidisciplinary oncology teams.
COBRA-LIKE 9 modulates cotton cell wall development via regulating cellulose deposition
Authors: He Qingfei , Yu Yujia , Qin Zhiguang , Duan Yujia , Liu Hanqiao , Li Weixi , Song Xiaohui , Zhu Guozhong , Shang Xiaoguang , Guo Wangzhen 
Published: December 2024

Abstract
Plant cell walls are complex and dynamic cellular structures critical for plant growth, development, physiology, and adaptation. Cellulose is one of the most important components of the cell wall. However, how cellulose microfibrils deposit and assemble into crystalline cellulose remains elusive. The COBRA-LIKE plant-specific protein family plays a vital role in modulating the deposition and orientation of cellulose microfibril in plant cell walls. Here, we investigate the role of GhCOBL9 in cotton (Gossypium hirsutum) fiber development, an ideal model for studying cell elongation and cell wall thickening. The expression period of GhCOBL9 is consistent with the thickening stage of the secondary wall of cotton fibers. Overexpression of GhCOBL9 results in increased cellulose content in the cell wall and produces shorter, thicker, and stronger fibers, while RNA interference (RNAi)-mediated downregulation of GhCOBL9 leads to the opposite phenotypes, indicating its crucial role in cell wall development. Subcellular localization and binding activity assays reveal that GhCOBL9 targets the cell wall and binds to crystalline cellulose with high affinity. Transcriptomic analysis of GhCOBL9 transgenic lines uncovers expression alterations in genes related to cellulose and monosaccharide biosynthesis. Furthermore, we identify a fasciclin-like arabinogalactan protein 9 (GhFLA9) as an interacting partner of GhCOBL9 to modulate cell wall development. Additionally, the R2R3-MYB transcription factor GhMYB46-5 activates GhCOBL9 expression by binding to the MYB46-responsive cis-regulatory element in the GhCOBL9 promoter. These findings broaden our knowledge of COBL function in modulating plant cell wall development.
The transcription factor ORA59 represses hypoxia responses during Botrytis cinerea infection and reoxygenation
Authors: Brunello Luca , Kunkowska Alicja B , Olmi Emma , Triozzi Paolo M , Castellana Simone , Perata Pierdomenico , Loreti Elena 
Published: December 2024

Abstract
Transcription factors belonging to the large ethylene response factor (ERF) family are involved in plant responses to biotic and abiotic stresses. Among the ERFs, OCTADECANOID-RESPONSIVE ARABIDOPSIS 59 (ORA59) integrates ethylene and jasmonic acid signaling to regulate resistance to necrotrophic pathogens. The ERF group ERFVII encodes oxygen-labile proteins that are required for oxygen sensing and are stabilized by hypoxia established at the site of Botrytis (Botrytis cinerea) infection. Here, we show that ORA59 represses ERFVII protein activity to induce the expression of hypoxia-responsive genes in Arabidopsis (Arabidopsis thaliana). Moreover, inhibition of ethanol fermentation enhances plant tolerance to Botrytis, indicating a trade-off between the hypoxia and defense responses. In addition, ERFVII members and ORA59 are both involved in the downregulation of hypoxia-responsive genes during reoxygenation. Taken together, our results reveal that the ERFVII transcription factor–ORA59 module ensures that the multiple roles of ERFVII proteins are correctly balanced to favor plant tolerance to biotic or abiotic stresses.
Improving Function in Older Adults With Hospital-Associated Deconditioning: Lessons Learned Comparing a Randomized Controlled Trial to Real World Practice
Authors: Garbin Alexander J , Tran Melissa K , Graber Jeremy , Derlein Danielle , Currier Deborah , Altic Rebecca , Will Robert , Cumbler Ethan , Forster Jeri E , Mangione Kathleen K , Stevens-Lapsley Jennifer E 
Published: December 2024

Abstract

Objective
The optimal approach for improving physical function following acute hospitalization is unknown. A recent clinical trial of home health physical therapy compared a high-intensity, progressive, multi-component (PMC) intervention to enhanced usual care (EUC). While both groups improved in physical function, no between-group differences were observed. However, the EUC group received care that differed from real world practice due to standardized treatments and a higher frequency of visits. This study compared a non-randomized true usual care (TUC) group to the EUC and PMC groups.

Methods
Participants in the parent trial were randomly assigned to the EUC group (n = 100) and PMC group (n = 100) following hospital discharge. A subset of eligible patients (n = 55) were concurrently enrolled in the TUC group. Both the PMC and EUC groups received strength, activities of daily living, and gait training that differed in intensity but were matched in frequency and duration. TUC group care was determined by the home health agency. The primary outcome at 60-days was the Short Physical Performance Battery (SPPB).

Results
In comparison to the TUC group, the EUC and PMC groups had significantly greater improvements in SPPB score (EUC: +1.04 points [CI = 0.18–1.90]; PMC: +1.12 points [CI = 0.23–2.00]).

Conclusion
While participants in the EUC and PMC groups experienced greater functional recovery compared to those in the TUC group, it cannot be determined whether these differences are due to the interventions received or confounding factors associated with the addition of a third, non-randomized, study group during the trial period.

Impact
This study illustrates the importance of design and interpretation of control groups for clinical trials. Further, the differences between the TUC group and the enhanced intervention groups warrant future research exploring whether increasing visits and standardizing care improve function in older adults receiving home health physical therapy after hospital associated deconditioning.

Lay summary
Participants in the intervention groups received standardized and more therapy than usual care, and experienced greater functional improvements. However, these differences may be due to factors associated with the addition of a non-randomized group during an ongoing clinical trial.