bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electromagnetic signatures of white dwarf collisions in AGN discs
Authors: Zhang Shu-Rui , Luo Yan , Wu Xiao-Jun , Wang Jian-Min , Ho Luis C , Yuan Ye-Fei 
Published: July 2023

ABSTRACT
In the inner region of the disc of an active galactic nucleus (AGN), the collision of two white dwarfs (WDs) through Jacobi capture might be inevitable, leading to a Type Ia supernova (SN Ia) explosion. This transient event, influenced by the disc gas and the gravity of the supermassive black hole (SMBH), exhibits distinct characteristics compared with normal SNe Ia. The energy of the explosion is mainly stored in the ejecta in the form of kinetic energy. Typically, the ejecta is not decelerated effectively by the AGN disc and rushes rapidly out of the AGN disc. However, under the influence of the SMBH, most of the ejecta falls back toward the AGN disc. As the fallback ejecta becomes more dispersed, it interacts with the disc gas, converting its kinetic energy into thermal energy. This results in a high-energy transient characterized by a rapid initial rise followed by a decay with L∝t−2.8. The time-scale of the transient ranges from hours to weeks, depending on the mass of the SMBH. This process generates high-energy radiation spanning from hard X-rays to the soft γ range. Additionally, the subsequent damage to the disc may result in changing-look AGNs. Moreover, the falling back of SNe Ia ejecta on to the AGN disc significantly increases the metallicity of the AGN and can even generate heavy elements within AGN discs.
MUSEQuBES: the relation between Ly α emitters and C iv absorbers at z ≈ 3.3
Authors: Banerjee Eshita , Muzahid Sowgat , Schaye Joop , Johnson Sean D , Cantalupo Sebastiano 
Published: July 2023

ABSTRACT
We present a detailed study of the column density and covering fraction profiles of C iv absorption around 86 redshift z ≈ 3.3 Ly α emitters (LAEs) detected in eight Multi-Unit Spectroscopic Explorer (MUSE) fields of 1 arcmin × 1 arcmin centred on eight bright background quasars as part of the MUSE Quasar-field Blind Emitters Survey (MUSEQuBES). Using Voigt profile fitting of all the C iv absorbers detected along these eight sightlines, we generated a ‘blind’ absorber catalogue consisting of 489 C iv absorption components. We cross-matched this blind C iv catalogue with the MUSE-detected LAE catalogue and found a significant enhancement of C iv components within ≈±400 $\rm km\, s^{-1}$ of the systemic redshifts of the LAEs. Neither the C iv column density (N) nor the Doppler parameter (b) of individual C iv components shows any significant anticorrelation with impact parameter (ρ) of the LAEs in the 68 percentile range of 90 ≤ ρ ≤ 230 physical kpc (pkpc). We find a covering fraction of ≈60 per cent for a threshold $N(\rm{C{\small IV}})$ of 1012.5 cm−2, which is roughly twice as high as in random regions. The C iv covering fraction remains constant at $\approx\!{50}{{\ \rm per\, cent}}$ for impact parameters in the range of 150–250 pkpc (≈3–6R200). Using the covering fraction profile, we constrain the LAE–C iv absorber two-point correlation function, and obtain $r_0 = 3.4^{+1.1}_{-1.0}$ comoving Mpc and $\gamma = 1.2^{+0.2}_{-0.3}$ for a threshold $N(\rm{C{\small IV}})$ of 1013.0 cm−2. The C iv covering fraction is found to be enhanced for the LAEs that are part of a ‘pair/group’ compared to the isolated ones.
Optically informed searches of high-energy neutrinos from interaction-powered supernovae
Authors: Pitik Tetyana , Tamborra Irene , Lincetto Massimiliano , Franckowiak Anna 
Published: July 2023

ABSTRACT
The interaction between the ejecta of supernovae (SNe) of Type IIn and a dense circumstellar medium can efficiently generate thermal ultraviolet/optical radiation and lead to the emission of neutrinos in the 1–103 TeV range. We investigate the connection between the neutrino signal detectable at the IceCube Neutrino Observatory and the electromagnetic signal observable by optical wide-field, high-cadence surveys to outline the best strategy for upcoming follow-up searches. We outline a semi-analytical model that connects the optical light-curve properties to the SN parameters and find that a large peak luminosity (${L_{\rm {peak}}\gtrsim 10^{43}{-}10^{44}\, \mathrm{erg \, s^{-1}}}$) and an average rise time (trise ≳ 10−40 d) are necessary for copious neutrino emission. Nevertheless, the most promising Lpeak and trise can be obtained for SN configurations that are not optimal for neutrino emission. Such ambiguous correspondence between the optical light-curve properties and the number of IceCube neutrino events implies that relying on optical observations only, a range of expected neutrino events should be considered (e.g. the expected number of neutrino events can vary up to two orders of magnitude for some among the brightest SNe IIn observed by the Zwicky Transient Facility up to now, SN 2020usa and SN 2020in). In addition, the peak in the high-energy neutrino curve should be expected a few trise after the peak in the optical light curve. Our findings highlight that it is crucial to infer the SN properties from multiwavelength observations rather than focusing on the optical band only to enhance upcoming neutrino searches.
Temperature fluctuations in quasar accretion discs from spectroscopic monitoring data
Authors: Stone Zachary , Shen Yue 
Published: July 2023

ABSTRACT
NK22 proposed a new method to reconstruct the temperature perturbation map (as functions of time and disc radius) of active galactic nuclei (AGN) accretion discs using multiwavelength photometric light curves. We apply their technique to 100 quasars at z = 0.5–2 from the Sloan Digital Sky Survey Reverberation Mapping project, using multi-epoch spectroscopy that covers rest-frame UV-optical continuum emission from the quasar and probes days to months time-scales. Consistent with NK22 for low-redshift AGNs, we find that the dominant pattern of disc temperature perturbations is either slow inward/outward moving waves with typical amplitudes $\delta T/T_0\sim 10~{{\ \rm per \, cent}}$ traveling at ∼0.01–0.1c, with a typical radial frequency of ∼ 0.5 dex in log R, or incoherent perturbations. In nearly none of the cases do we find clear evidence for coherent, fast outgoing temperature perturbations at the speed of light, reminiscent of the lamppost model; but such lamppost signals may be present in some quasars for limited periods of the monitoring data. Using simulated data, we demonstrate that high-fidelity temperature perturbation maps can be recovered with high-quality monitoring spectroscopy, with limited impact from seasonal gaps in the data. On the other hand, reasonable temperature perturbation maps can be reconstructed with high-cadence photometric light curves from the Vera C Rubin Observatory Legacy Survey of Space and Time. Our findings, together with NK22, suggest that internal disc processes are the main driver for temperature fluctuations in AGN accretion discs over days to months time-scales.
Weibel-dominated quasi-perpendicular shock: hybrid simulations and in situ observations
Authors: Kropotina J A , Petrukovich A A , Chugunova O M , Bykov A M 
Published: July 2023

ABSTRACT
We directly compare hybrid kinetic simulations and in situ observations of a high Mach number high-β shock in the Solar wind. We launch virtual probes to demonstrate that the model quantitatively reproduces the observations. The observed wave properties are caused by the ion Weibel instability in the shock foot. Parameters of reflected ions in the shock foot are extracted from simulations, and their coordinate dependencies are linearly approximated. These approximations could be used in analytical models. Due to strong magnetic variations at ramp the reflected ions density can be locally very high (nearly that of the incoming flow), which makes favourable conditions for the instability.
Measuring the hot ICM velocity structure function using XMM–Newton observations
Authors: Gatuzz Efrain , Mohapatra R , Federrath C , Sanders J S , Liu A , Walker S A , Pinto C 
Published: July 2023

ABSTRACT
It has been shown that the gas velocities within the intracluster medium (ICM) can be measured by applying the novel XMM–Newton EPIC-pn energy scale calibration, which uses instrumental Cu Kα as reference for the line emission. Using this technique, we have measured the velocity distribution of the ICM for clusters involving AGN feedback and sloshing of the plasma within the gravitational well (Virgo and Centaurus) and a relaxed one (Ophiuchus). We present a detailed study of the kinematics of the hot ICM for these systems. First, we compute the velocity probability distribution functions (PDFs) from the velocity maps. We find that for all sources, the PDF follows a normal distribution, with a hint of a multimodal distribution in the case of Ophiuchus. Then, we compute the velocity structure function (VSF) for all sources in order to study the variation with scale as well as the nature of turbulence in the ICM. We measure a turbulence driving scale of ∼10–20 kpc for the Virgo cluster, while the Ophiuchus cluster VSF reflects the absence of strong interaction between the ICM and a powerful Active Galactic Nucleus (AGN) at such spatial scales. For the former, we compute a dissipation time larger than the jet activity cycle, thus indicating that a more efficient heating process than turbulence is required to reach equilibrium. This is the first time that the VSF of the hot ICM has been computed using direct velocity measurements from X-ray astronomical observations.
Restoration of T80-S telescope’s images using neural networks
Authors: Bernardi Rafael L , Berdja Amokrane , Guzmán Christian Dani , Torres-Torriti Miguel , Roth Martin M 
Published: July 2023

ABSTRACT
Convolutional neural networks (CNNs) have been used for a wide range of applications in astronomy, including for the restoration of degraded images using a spatially invariant point spread function (PSF) across the field of view. Most existing development techniques use a single PSF in the deconvolution process, which is unrealistic when spatially variable PSFs are present in real observation conditions. Such conditions are simulated in this work to yield more realistic data samples. We propose a method that uses a simulated spatially variable PSF for the T80-South (T80-S) telescope, an 80-cm survey imager at Cerro Tololo (Chile). The synthetic data use real parameters from the detector noise and atmospheric seeing to recreate the T80-S observational conditions for the CNN training. The method is tested on real astronomical data from the T80-S telescope. We present the simulation and training methods, the results from real T80-S image CNN prediction, and a comparison with space observatory Gaia. A CNN can fix optical aberrations, which include image distortion, PSF size and profile, and the field position variation while preserving the source’s flux. The proposed restoration approach can be applied to other optical systems and to post-process adaptive optics static residual aberrations in large-diameter telescopes.
Measurement of diet quality among First Nations peoples in Canada and associations with health: a scoping review
Authors: Sebai Ines , Deaconu Ana , Mobetty Fabrice , Nardocci Milena , Ing Amy , Batal Malek 
Published: July 2023

Abstract

Background
Given the increasing number and the diversity of dietary quality indices used for research, and the differences between settings, there is a need to identify valid indices of dietary quality in different contexts and populations and to identify their associations with health-related outcomes.

Objectives
The primary objective of this scoping review is to identify the tools used in determining dietary quality among First Nations and to describe the changes in diet. The second objective is to describe the associations identified in studies that have measured the relationship between health and dietary quality among First Nations; and the third objective is to identify factors associated with diet quality.

Methods
PubMed, Embase, CINAHL, Global Health, and Web of Science were searched from inception to June 2021 and updated in February 2022. Articles were included if the research subjects were First Nations, or if articles reported disaggregated subset data for First Nations. Eligible studies focused on nutrition and diet and were published in English or French.

Results
A total of 151 articles were included in the analysis. Studies used several indicators to measure if individuals adhered to dietary guidelines. Traditional food consumption was frequently used as an indicator of diet quality (n = 96). The consumption of store-bought foods was used as an indicator in 28 studies. Some studies used other diet quality indicators such as the Healthy Eating Index (n = 5) and ultra-processed food “NOVA” classification (n = 6). A trend for decreasing traditional food intake over time was apparent, alongside an increase in store-bought food intake. This trend was accompanied with declining health status, including the increased prevalence of overweight and obesity, diabetes, metabolic diseases, and dental caries.

Conclusion
This scoping review showed that diet quality among First Nations is improved when traditional foods are consumed. Reduced diet quality was associated with increased risk of noncommunicable diseases.
Performance of serum biomarkers reflective of different pathogenic processes in systemic sclerosis-associated interstitial lung disease
Authors: Györfi Andrea-Hermina , Filla Tim , Dickel Nicholas , Möller Florian , Li Yi-Nan , Bergmann Christina , Matei Alexandru-Emil , Harrer Thomas , Kunz Meik , Schett Georg , Distler Jörg H W 
Published: July 2023

Abstract

Objective
Interstitial lung disease (ILD) is the leading cause of mortality in SSc. Novel biomarkers are crucial to improve outcomes in SSc-ILD. We aimed to compare the performance of potential serum biomarkers of SSc-ILD that reflect different pathogenic processes: KL-6 and SP-D (epithelial injury), CCL18 (type 2 immune response), YKL-40 (endothelial injury and matrix remodelling) and MMP-7 (ECM remodelling).

Methods
Baseline and follow-up serum samples from 225 SSc patients were analysed by ELISA. Progressive ILD was defined according to the 2022-ATS/ERS/JRS/ALAT guidelines. Linear mixed models and random forest models were used for statistical analyses.

Results
Serum levels of KL-6 [MD 35.67 (95% CI 22.44–48.89, P &lt; 0.01)], SP-D [81.13 (28.46–133.79, P &lt; 0.01)], CCL18 [17.07 (6.36–27.77, P &lt; 0.01)], YKL-40 [22.81 (7.19–38.44, P &lt; 0.01)] and MMP-7 [2.84 (0.88–4.80, P &lt; 0.01)] were independently associated with the presence of SSc-ILD. A machine-learning model including all candidates classified patients with or without ILD with an accuracy of 85%. The combination of KL-6 and SP-D was associated with the presence [0.77 (0.53–1.00, P’ &lt;0.01)] and previous progression of SSc-ILD [OR 1.28 (1.01–1.61, P’ =0.047)]. Higher baseline levels of KL-6 [OR 3.70 (1.52–9.03, P &lt; 0.01)] or SP-D [OR 2.00 (1.06–3.78, P = 0.03)] increased the odds of future SSc-ILD progression, independent of other conventional risk factors, and the combination of KL-6 and SP-D [1.109 (0.665–1.554, P &lt; 0.01)] showed improved performance compared with KL-6 and SP-D alone.

Conclusion
All candidates performed well as diagnostic biomarkers for SSc-ILD. The combination of KL-6 and SP-D might serve as biomarker for the identification of SSc patients at risk of ILD progression.
Using connectome-based models of working memory to predict emotion regulation in older adults
Authors: Fisher Megan E , Teng James , Gbadeyan Oyetunde , Prakash Ruchika S 
Published: July 2023

Abstract
Older adulthood is characterized by enhanced emotional well-being potentially resulting from greater reliance on adaptive emotion regulation strategies. However, not all older adults demonstrate an increase in emotional well-being and instead rely on maladaptive emotion regulation strategies. An important moderator of age-related shifts in strategy preferences is working memory (WM) and its underlying neural circuitry. As such, individual differences in the neural integrity underlying WM may predict older adults’ emotion regulation strategy preferences. Our study used whole-brain WM networks—derived from young adults using connectome-based predictive modeling—to predict WM performance and acceptance strategy use in healthy older adults. Older adults (N = 110) completed baseline assessments as part of a randomized controlled trial examining the impact of mind-body interventions on healthy aging. Our results revealed that the WM networks predicted WM accuracy but not acceptance use or difficulties in emotion regulation in older adults. Individual differences in WM performance, but not WM networks, moderated relationships between image intensity and acceptance use. These findings highlight that robust neural markers of WM generalize to an independent sample of healthy older adults but may not generalize beyond cognitive domains to predict emotion-based behaviors.
Impact of early antiretroviral therapy, early life immunity and immune sex differences on HIV disease and posttreatment control in children
Authors: Herbert Nicholas G. , Goulder Philip J.R. 
Published: July 2023

Purpose of review
To review recent insights into the factors affecting HIV disease progression in children living with HIV, contrasting outcomes: following early ART initiation with those in natural, antiretroviral therapy (ART)-naive infection; in children versus adults; and in female individuals versus male individuals.

Recent findings
Early life immune polarization and several factors associated with mother-to-child transmission of HIV result in an ineffective HIV-specific CD8+ T-cell response and rapid disease progression in most children living with HIV. However, the same factors result in low immune activation and antiviral efficacy mediated mainly through natural killer cell responses in children and are central features of posttreatment control. By contrast, rapid activation of the immune system and generation of a broad HIV-specific CD8+ T-cell response in adults, especially in the context of ‘protective’ HLA class I molecules, are associated with superior disease outcomes in ART-naive infection but not with posttreatment control. The higher levels of immune activation in female individuals versus male individuals from intrauterine life onwards increase HIV infection susceptibility in females in utero and may favour ART-naive disease outcomes rather than posttreatment control.

Summary
Early-life immunity and factors associated with mother-to-child transmission typically result in rapid HIV disease progression in ART-naive infection but favour posttreatment control in children following early ART initiation.
Decrypting biological hallmarks of aging in people with HIV
Authors: Premeaux Thomas A. , Ndhlovu Lishomwa C. 
Published: July 2023

Purpose of review
HIV infection adds further complexity to the heterogenous process of aging. In this focused review, we examine and discuss recent advances to better elucidate mechanisms of biological aging perturbed and accelerated in the context of HIV, particularly among those with viral suppression through the benefits of antiretroviral therapy (ART). New hypotheses from these studies are poised to provide an improved understanding of multifaceted pathways that converge and likely form the basis for effective interventions toward successful aging.

Recent findings
Evidence to date suggests multiple mechanisms of biological aging impact people living with HIV (PLWH). Recent literature delves and expands on how epigenetic alterations, telomere attrition, mitochondrial perturbations, and intercellular communications may underpin accelerated or accentuated aging phenotypes and the disproportionate prevalence of age-related complications among PLWH. Although most hallmarks of aging are likely exacerbated in the setting of HIV, ongoing research efforts are providing new insight on the collective impact these conserved pathways may have in the aging disease processes.

Summary
New knowledge on underlying molecular disease mechanisms impacting people aging with HIV are reviewed. Also examined are studies that may facilitate the development and implementation of effective therapeutics and guidance on improving geriatric HIV clinical care.
Algorithmic Fairness of Machine Learning Models for Alzheimer’s Disease Progression Prediction
Authors: Yuan Chenxi , Linn Kristin A. , Hubbard Rebecca A. ,   Alzheimer’s Disease Neuroimaging Initiative
Published: July 2023

ABSTRACTIntroductionAlzheimer’s disease (AD) disproportionately affects older adults from marginalized communities. Predictive models using machine learning (ML) techniques have potential to improve early detection and management of AD. However, ML models potentially suffer from biases and may perpetuate or exacerbate existing disparities.MethodsWe investigated algorithmic fairness of logistic regression, support vector machines and recurrent neural networks for predicting progression to mild cognitive impairment and AD. Fairness was quantified across gender, ethnicity, and race subgroups using three measures: equal opportunity, equalized odds and demographic parity.ResultsAll three ML models performed well in aggregate but demonstrated disparate performance across race and ethnicity subgroups. Compared to Non-Hispanic participants, sensitivity for predicting progression to mild cognitive impairment and to AD was 5%-9.6% and 16.8%-24.9% lower, respectively, for Hispanic participants. Sensitivity was similarly lower for Black and Asian participants compared to Non-Hispanic White participants. Models generally satisfied metrics of fairness with respect to gender.DiscussionAlthough accurate in aggregate, models failed to satisfy fairness metrics. Fairness should be considered in the development and deployment of ML models for AD progression.