bluuebunny/crossref_metadata_2025_split huggingface dataset:
Probing spectral and timing properties of the X-ray pulsar RX J0440.9 + 4431 in the giant outburst of 2022–2023
Authors: Mandal Manoj , Sharma Rahul , Pal Sabyasachi , Jaisawal G K , Gendreau Keith C , Ng Mason , Sanna Andrea , Malacaria Christian , Tombesi Francesco , Ferrara E C , Markwardt Craig B , Wolff Michael T , Coley Joel B 
Published: September 2023

ABSTRACT
The X-ray pulsar RX J0440.9 + 4431 went through a giant outburst in 2022 and reached a record-high flux of 2.3 Crab, as observed by Swift/BAT. We study the evolution of different spectral and timing properties of the source using NICER observations. The pulse period is found to decrease from 208 s to 205 s, and the pulse profile evolves significantly with energy and luminosity. The hardness ratio and hardness intensity diagram (HID) show remarkable evolution during the outburst. The HID turns towards the diagonal branch from the horizontal branch above a transition (critical) luminosity, suggesting the presence of two accretion modes. Each NICER spectrum can be described using a cutoff power law with a blackbody component and a Gaussian at 6.4 keV. At higher luminosities, an additional Gaussian at 6.67 keV is used. The observed photon index shows negative and positive correlations with X-ray flux below and above the critical luminosity, respectively. The evolution of spectral and timing parameters suggests a possible change in the emission mechanism and beaming pattern of the pulsar depending on the spectral transition to sub- and supercritical accretion regimes. Based on the critical luminosity, the magnetic field of the neutron star can be estimated in the order of 1012 or 1013 G, assuming different theoretical models. Moreover, the observed iron emission line evolves from a narrow to a broad feature with luminosity. Two emission lines originating from neutral and highly ionized Fe atoms are evident in the spectra around 6.4 and 6.67 keV (later is seen only in higher luminosities).
The FAST Galactic Plane Pulsar Snapshot survey – IV. Discovery of five fast radio bursts
Authors: Zhou D J , Han J L , Jing W C , Wang P F , Wang C , Wang T , Wang W-Y , Luo R , Xu J , Xu R X , Wang H G 
Published: September 2023

ABSTRACT
We report five new fast radio bursts (FRBs) discovered from the Galactic Plane Pulsar Snapshot (GPPS) survey by the Five-hundred-meter Aperture Spherical radio Telescope (FAST): FRB 20210126, FRB 20210208, FRB 20210705, FRB 20211005, and FRB 20220306. To date, no repeating bursts from these FRB sources have been detected in the follow-up monitoring observations, leading to their classification as potential one-off events. We obtain the basic parameters for these bursts, including position, dispersion measure, pulse width, spectral index, scattering time-scale, etc. The fluences and flux densities are generally lower in comparison to the values observed in one-off bursts discovered by other telescopes. Among the observed bursts, polarization data for four bursts were recorded during observations. Consequently, we obtain polarization profiles and Faraday rotation measures for these bursts.
Fast and efficient identification of anomalous galaxy spectra with neural density estimation
Authors: Böhm Vanessa , Kim Alex G , Juneau Stéphanie 
Published: September 2023

ABSTRACT
Current large-scale astrophysical experiments produce unprecedented amounts of rich and diverse data. This creates a growing need for fast and flexible automated data inspection methods. Deep learning algorithms can capture and pick up subtle variations in rich data sets and are fast to apply once trained. Here, we study the applicability of an unsupervised and probabilistic deep learning framework, the probabilistic auto-encoder, to the detection of peculiar objects in galaxy spectra from the SDSS survey. Different to supervised algorithms, this algorithm is not trained to detect a specific feature or type of anomaly, instead it learns the complex and diverse distribution of galaxy spectra from training data and identifies outliers with respect to the learned distribution. We find that the algorithm assigns consistently lower probabilities (higher anomaly score) to spectra that exhibit unusual features. For example, the majority of outliers among quiescent galaxies are E+A galaxies, whose spectra combine features from old and young stellar population. Other identified outliers include LINERs, supernovae, and overlapping objects. Conditional modelling further allows us to incorporate additional information. Namely, we evaluate the probability of an object being anomalous given a certain spectral class, but other information such as metrics of data quality or estimated redshift could be incorporated as well. We make our code publicly available.
Statistics of tidal and deformation eigenvalue fields in the primordial Gaussian matter distribution: the two-dimensional case
Authors: Feldbrugge Job , Yan Yihan , van de Weygaert Rien 
Published: September 2023

ABSTRACT
We study the statistical properties of the eigenvalues of the primordial tidal and deformation tensor for two-dimensional random Gaussian cosmic density fields. With the tidal and deformation tensors, Hessians of the gravitational and velocity potential, being Gaussian, the eigenvalue fields are distinctly non-Gaussian. We extend the Doroshkevich formula for the joined distribution of eigenvalues to two-dimensional fields and evaluate the two- and three-point correlation functions. In addition, we assess the number densities of singular points of the eigenvalue fields and find their corresponding two- and three-point correlation functions. The incentive for the present study is based on our interest in developing a fully analytical theory for the structure and dynamics of the cosmic web. The tidal forces and the resulting mass element deformation shape the prominent anisotropic wall-like and filamentary components of the cosmic web. Less well-known is that the web-like spatial pattern is already recognizable in the primordial tidal and deformation eigenvalue field. Against the full phase-space assessment of structure formation in the Universe, the caustic skeleton theory entails an analytical framework for the non-linear evolution of the cosmic web. It accomplishes this by describing the folding of the dark matter sheet and quantifying the emerging caustic singularities, which are fully specified by the spatial properties of the deformation eigenvalues and eigenvectors. Finally, the eigenvalues of the primordial tidal tensor are crucial in the generation of the angular momentum of galaxies. Understanding their spatial distribution is a critical element in predicting the resulting rotation amplitude and orientation.
Can diffusion model conditionally generate astrophysical images?
Authors: Zhao Xiaosheng , Ting Yuan-Sen , Diao Kangning , Mao Yi 
Published: September 2023

ABSTRACT
Generative adversarial networks (GANs) are frequently utilized in astronomy to construct an emulator of numerical simulations. Nevertheless, training GANs can prove to be a precarious task, as they are prone to instability and often lead to mode collapse problems. Conversely, the diffusion model also has the ability to generate high-quality data without adversarial training. It has shown superiority over GANs with regard to several natural image data sets. In this study, we undertake a quantitative comparison between the denoising diffusion probabilistic model (DDPM) and StyleGAN2 (one of the most robust types of GANs) via a set of robust summary statistics from scattering transform. In particular, we utilize both models to generate the images of 21 cm brightness temperature mapping, as a case study, conditionally based on astrophysical parameters that govern the process of cosmic reionization. Using our new Fréchet Scattering Distance (FSD) as the evaluation metric to quantitatively compare the sample distribution between generative models and simulations, we demonstrate that DDPM outperforms StyleGAN2 on varied sizes of training sets. Through Fisher forecasts, we demonstrate that on our data sets, StyleGAN2 exhibits mode collapses in varied ways, while DDPM yields a more robust generation. We also explore the role of classifier-free guidance in DDPM and show the preference for a non-zero guidance scale only when the training data is limited. Our findings indicate that the diffusion model presents a promising alternative to GANs in the generation of accurate images. These images can subsequently provide reliable parameter constraints, particularly in the realm of astrophysics.
Potential signature of a quadrupolar hubble expansion in Pantheon+supernovae
Authors: Cowell Jessica A , Dhawan Suhail , Macpherson Hayley J 
Published: September 2023

ABSTRACT
The assumption of isotropy – that the Universe looks the same in all directions on large scales – is fundamental to the standard cosmological model. It is therefore critical to empirically test in which regimes this assumption holds. Anisotropies in the cosmic expansion are expected due to non-linear structures in the late Universe. However, the extent to which these anisotropies might impact our low-redshift observations remains to be fully tested. We use general relativistic simulations to determine that the expected anisotropies in the Hubble and deceleration parameters are quadrupolar and dipolar, respectively. We constrain these multipoles simultaneously in the new Pantheon+supernova compilation. In the rest frame of the cosmic microwave background (CMB), including peculiar velocity (PV) corrections, we find an ∼2σ deviation from isotropy. We constrain the eigenvalues of the quadrupole in the Hubble parameter to be λ1 = 0.021 ± 0.011 and λ2 = 0.00 ± 0.012 and place a 1σ upper limit on its amplitude of 2.88 per cent. We find no significant dipole in the deceleration parameter, with amplitude $q_{\rm dip} = 4.5^{+1.9}_{-5.4}$. However, in the rest frame of the CMB without PV corrections, we find a &gt;2σ positive amplitude with $q_{ \rm dip} = 9.6^{+4.0}_{-6.9}$. Incorporating these anisotropies, the monopole of the Hubble parameter shifts by only 0.30 km s−1 Mpc−1 with respect to the isotropic constraints.
The evolution of enclosed nesting in passerines is shaped by competition, energetic costs, and predation threat
Authors: Vanadzina Karina , Street Sally E , Sheard Catherine 
Published: September 2023

Abstract
Many avian species breed in enclosed nests that may provide better protection against predation and climatic conditions compared to open nests and are generally associated with larger clutch sizes and slower offspring growth. Here we show that different enclosed nesting strategies are each linked to behaviors with very different costs and benefits on a macroevolutionary scale. Using a detailed dataset of nest structure and location from the order Passeriformes, we employed phylogenetic comparative methods to evaluate (1) how predation, competition, design complexity, and energetic costs have shaped evolutionary transitions between different nesting strategies, and (2) whether these strategies also have distinct relationships with life-history traits. We find that flexible strategies (i.e., nesting in both open and enclosed sites) as well as energetically demanding strategies are evolutionarily unstable, indicating the presence of underlying ecological tradeoffs between antipredator protections, construction costs, and competition. We confirm that species with enclosed nests have larger clutch sizes and longer development and nestling periods compared to open nesters, but only species that construct enclosed nests rather than compete for preexisting cavities spend more time incubating and are concentrated in the tropics. Flexible strategies prevail in seasonal environments and are linked to larger clutches—but not longer development—compared to nesting in the open. Overall, our results suggest that predation, competition, and energetic costs affect the evolution of nesting strategies, but via distinct pathways, and that caution is warranted when generalizing about the functions of enclosed nest designs in birds.
The phased short-interfering RNA siRD29(-) regulates GIBBERELLIN 3-OXIDASE 3 during stolon-to-tuber transitions in potato
Authors: Malankar Nilam N , Kondhare Kirtikumar R , Saha Kishan , Mantri Mohit , Banerjee Anjan K 
Published: September 2023

Abstract
Phased short-interfering RNAs (phasiRNAs) fine tune various stages of growth, development, and stress responses in plants. Potato (Solanum tuberosum) tuberization is a complex process, wherein a belowground modified stem (stolon) passes through developmental stages like swollen stolon and minituber before it matures to a potato. Previously, we identified several phasiRNA-producing loci (PHAS) from stolon-to-tuber transition stages. However, whether phasiRNAs mediate tuber development remains unknown. Here, we show that a gene encoding NB-ARC DOMAIN-CONTAINING DISEASE RESISTANCE PROTEIN (StRGA4; a PHAS locus) is targeted by Stu-microRNA482c to generate phasiRNAs. Interestingly, we observed that one of the phasiRNAs, referred as short-interfering RNA D29(-), i.e. siRD29(-), targets the gibberellin (GA) biosynthesis gene GIBBERELLIN 3-OXIDASE 3 (StGA3ox3). Since regulation of bioactive GA levels in stolons controls tuber development, we hypothesized that a gene regulatory module, Stu-miR482c-StRGA4-siRD29(-)-StGA3ox3, could govern tuber development. Through transient expression assays and small RNA sequencing, generation of siRD29(-) and its phase was confirmed in planta. Notably, the expression of StGA3ox3 was higher in swollen stolon compared to stolon, whereas siRD29(-) showed a negative association with StGA3ox3 expression. Antisense (AS) lines of StGA3ox3 produced more tubers compared to wild type. As expected, StRGA4 overexpression (OE) lines had high levels of siRD29(-) and mimicked the phenotypes of StGA3ox3-AS lines, indicating the functionality of this module in potato. In vitro tuberization assays (with or without a GA inhibitor) using StGA3ox3 antisense lines and overexpression lines of StGA3ox3 or StRGA4 revealed that StGA3ox3 controls the tuber stalk development. Taken together, our findings suggest that a phasiRNA, siRD29(-), mediates the regulation of StGA3ox3 during stolon-to-tuber transitions in potato.
Association Between Hospital Participation in Value-Based Programs and Timely Initiation of Post-Acute Home Health Care, Functional Recovery, and Hospital Readmission After Joint Replacement
Authors: Roy Indrakshi , Karmarkar Amol M , Lininger Monica R , Jain Tarang , Martin Brook I , Kumar Amit 
Published: September 2023

Abstract

Objectives
This study examined the association between hospital participation in Bundled Payments for Care Improvement (BPCI) or Comprehensive Care for Joint Replacement (CJR) and the timely initiation of home health rehabilitation services for lower extremity joint replacements. Furthermore, this study examined the association between the timely initiation of home health rehabilitation services with improvement in self-care, mobility, and 90-day hospital readmission.

Method
This retrospective cohort study used Medicare inpatient claims and home health assessment data from 2016 to 2017 for older adults discharged to home with home health following hospitalization after joint replacement. Multilevel multivariate logistic regression was used to examine the association between hospital participation in BPCI or CJR programs and timely initiation of home health rehabilitation service. A 2-staged generalized boosted model was used to examine the association between delay in home health initiation and improvement in self-care, mobility, and 90-day risk-adjusted hospital readmission.

Results
Compared with patients discharged from hospitals that did not have BPCI or CJR, patients discharged from hospitals with these programs had a lower likelihood of delayed initiation of home health rehabilitation services for both knees and hip replacement. Using propensity scores as the inverse probability of treatment weights, delay in the initiation of home health rehabilitation services was associated with lower improvement in self-care (odds ratio [OR] = 1.23; 95% CI = 1.20–1.26), mobility (OR = 1.15; 95% CI = 1.13–1.18), and higher rate of 90-day hospital readmission (OR = 1.19; 95% CI = 1.15–1.24) for knee replacement. Likewise, delayed initiation of home health rehabilitation services was associated with lower improvement in self-care (OR = 1.16; 95% CI = 1.13–1.20) and mobility (OR = 1.26; 95% CI = 1.22–1.30) for hip replacement.

Conclusion
Hospital participation in BPCI or comprehensive CJR was associated with early home health rehabilitation care initiation, which was further associated with significant increases in functional recovery and lower risks of hospital readmission.

Impact
Policy makers may consider incentivizing health care providers to initiate early home health services and care coordination in value-based payment models.
The risk of major adverse cardiovascular events in patients with systemic sclerosis: a nationwide, population-based cohort study
Authors: Yen Tsai-Hung , Chen Yun-Wen , Hsieh Tsu-Yi , Chen Yi-Ming , Huang Wen-Nan , Chen Yi-Hsing , Chen Hsin-Hua 
Published: September 2023

Abstract

Objective
The objective of this study was to assess the incidence and risk factors of major adverse cardiovascular events (MACEs) in patients with systemic sclerosis (SSc).

Methods
We conducted a nationwide, population-based, cohort study using Taiwan’s National Health Insurance Research Database. We performed propensity score matching (PSM) using a 1:2 ratio, resulting in inclusion of 1379 patients with SSc and 2758 non-SSc individuals in the analysis. We assessed the association between SSc and MACEs, using the multivariable Cox proportional hazard regression model with adjustment of time-dependent covariates, and investigated risk factors for MACEs in patients with SSc, shown as adjusted hazard ratios (aHRs) with 95% CIs.

Results
SSc was not significantly associated with the risk of MACEs (aHR 1.04; 95% CI 0.77–1.42). Nevertheless, SSc was associated with increased risk of myocardial infarction [incidence rate ratio (IRR) 1.76; 95% CI 1.08–2.86] and peripheral arterial occlusion disease (IRR 3.67; 95% CI 2.84–4.74) but not of ischaemic stroke (IRR 0.89; 95% CI 0.61–1.29). Factors independently associated with MACEs in SSc patients included age (aHR 1.02), male gender (aHR 2.01), living in a suburban area (aHR 2.09), living in a rural area (aHR 3.00), valvular heart disease (aHR 4.26), RA (aHR 2.14), use of clopidogrel (aHR 26.65), and use of aspirin (aHR 5.31).

Conclusions
The risk of MACEs was not significantly increased in Taiwanese patients with SSc, and our investigation effectively identified the factors independently associated with MACEs in SSc patients. Additionally, patients with SSc exhibited higher risks of myocardial infarction and peripheral arterial occlusion disease but not of ischaemic stroke.
Fast and Accurate Maximum-Likelihood Estimation of Multi-Type Birth–Death Epidemiological Models from Phylogenetic Trees
Authors: Zhukova Anna , Hecht Frédéric , Maday Yvon , Gascuel Olivier 
Published: September 2023

Abstract
Multi-type birth–death (MTBD) models are phylodynamic analogies of compartmental models in classical epidemiology. They serve to infer such epidemiological parameters as the average number of secondary infections Re and the infectious time from a phylogenetic tree (a genealogy of pathogen sequences). The representatives of this model family focus on various aspects of pathogen epidemics. For instance, the birth–death exposed-infectious (BDEI) model describes the transmission of pathogens featuring an incubation period (when there is a delay between the moment of infection and becoming infectious, as for Ebola and SARS-CoV-2), and permits its estimation along with other parameters. With constantly growing sequencing data, MTBD models should be extremely useful for unravelling information on pathogen epidemics. However, existing implementations of these models in a phylodynamic framework have not yet caught up with the sequencing speed. Computing time and numerical instability issues limit their applicability to medium data sets (≤ 500 samples), while the accuracy of estimations should increase with more data.
We propose a new highly parallelizable formulation of ordinary differential equations for MTBD models. We also extend them to forests to represent situations when a (sub-)epidemic started from several cases (e.g., multiple introductions to a country). We implemented it for the BDEI model in a maximum likelihood framework using a combination of numerical analysis methods for efficient equation resolution. Our implementation estimates epidemiological parameter values and their confidence intervals in two minutes on a phylogenetic tree of 10,000 samples. Comparison to the existing implementations on simulated data shows that it is not only much faster but also more accurate. An application of our tool to the 2014 Ebola epidemic in Sierra-Leone is also convincing, with very fast calculation and precise estimates. As MTBD models are closely related to Cladogenetic State Speciation and Extinction (ClaSSE)-like models, our findings could also be easily transferred to the macroevolution domain.
Do Children With Medicaid Insurance Have Increased Revision Rates 5 Years After Posterior Spinal Fusions?
Authors: Moore Harold G. , Patibandla Sahiti D. , McClung Anna M. , Grauer Jonathan N. , Sucato Daniel J. , Wise Carol A. , Johnson Megan E. , Rathjen Karl E. , McIntosh Amy L. , Ramo Brandon A. , Brooks Jaysson T. 
Published: September 2023

Background:Socioeconomic disparities in musculoskeletal care are increasingly recognized, however, no studies to date have investigated the role of the insurance carrier on outcomes after posterior spinal fusion (PSF) with segmental spinal instrumentation for adolescent idiopathic scoliosis (AIS).Methods:A US insurance dataset was queried using the PearlDiver Mariner software for all patients aged 10 to 18 undergoing PSF for a primary diagnosis of AIS between 2010 and 2020. Age, sex, geographic region, number of levels fused, and baseline medical comorbidities were queried. Complications occurring within 90 days of the index surgery were queried using theInternational Classification of Diseases, Ninth Revision(ICD-9) andInternational Classification of Diseases, 10th Revision(ICD-10) codes. Revision surgery was also queried up to 5 years after the index PSF. Categorical variables were compared using the Fisher χ2tests and continuous variables were compared using independentttests. All-cause revision within 5 years was compared using the Kaplan-Meier analysis and a log-rank test. Significance was set atP-value <0.05.Results:A total of 10,794 patients were identified with 9006 (83.4%) patients with private insurance and 1788 (16.6%) patients insured by Medicaid. The mean follow-up in the database was 5.36±3 years for patients with private insurance and 4.78±2.9 years for patients with Medicaid insurance (P<0.001). Children with AIS and Medicaid insurance had a significantly higher prevalence of asthma, hypertension, and obesity. A larger percentage of children with Medicaid insurance (41.3%) underwent a ≥13-level PSF compared with privately insured children (34.5%) (P<0.001). Medicaid patients did not experience higher odds of postoperative complications; in addition, revision surgeries occurred in 1.1% and 1.8% of patients with private insurance and Medicaid insurance, respectively at 5 years postoperatively (P=0.223).Conclusion:Despite worse baseline comorbidities and longer fusion constructs, AIS patients insured with Medicaid did not have higher rates of complications or revisions at 5-year follow-up versus privately insured patients.Level of Evidence:Level III—retrospective cohort study.