bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the environmental influence of groups and clusters of galaxies beyond the virial radius: Galactic conformity at few Mpc scales
Authors: Lacerna Ivan , Rodriguez Facundo , Montero-Dorta Antonio D , O’Mill Ana L , Cora Sofía A , Artale M Celeste , Ruiz Andrés N , Hough Tomás , Vega-Martínez Cristian A 
Published: April 2022

ABSTRACT
The environment within dark matter haloes can quench the star formation of galaxies. However, environmental effects beyond the virial radius of haloes (≳1 Mpc) are less evident. An example is the debated correlation between colour or star formation in central galaxies and neighbour galaxies in adjacent haloes at large separations of several Mpc, referred to as two-halo galactic conformity. We use two galaxy catalogues generated from different versions of the semi-analytic model sag applied to the mdpl2 cosmological simulation and the IllustrisTNG300 cosmological hydrodynamical simulation to study the two-halo conformity by measuring the quenched fraction of neighbouring galaxies as a function of the real-space distance from central galaxies. We find that low-mass central galaxies in the vicinity of massive systems (M200c ≥ 1013$h^{-1}~\rm M_{\odot }$) out to 5 $h^{-1}~\rm Mpc$ are preferentially quenched compared to other central galaxies at fixed stellar mass M⋆ or fixed host halo mass M200c at z ∼ 0. In all the galaxy catalogues is consistent that the low-mass (M⋆ &lt; 1010$h^{-1}~\rm M_{\odot }$ or M200c &lt; 1011.8$h^{-1}~\rm M_{\odot }$) central galaxies in the vicinity of clusters and, especially, groups of galaxies mostly produce the two-halo galactic conformity. On average, the quenched low-mass central galaxies are much closer to massive haloes than star-forming central galaxies of the same mass (by a factor of ∼ 5). Our results agree with other works regarding the environmental influence of massive haloes that can extend beyond the virial radius and affect nearby low-mass central galaxies.
Dusty circumbinary discs: inner cavity structures and stopping locations of migrating planets
Authors: Coleman Gavin A L , Nelson Richard P , Triaud Amaury H M J 
Published: April 2022

ABSTRACT
We present the results of two-fluid hydrodynamical simulations of circumbinary discs consisting of gas and dust, with and without embedded planets, to examine the influence of the dust on the structure of the tidally truncated inner cavity and on the parking locations of migrating planets. In this proof-of-concept study, we consider Kepler-16 and Kepler-34 analogues, and examine dust fluids with Stokes numbers in the range 10−4 ≤ St ≤ 10−1 and dust-to-gas ratios of 0.01 and 1. For the canonical dust-to-gas ratio of 0.01, we find the inclusion of the dust has only a minor effect on the cavity and stopping locations of embedded planets compared to dust-free simulations. However, for the enhanced dust-to-gas ratio of unity, assumed to arise because of significant dust drift and accumulation, we find that the dust can have a dramatic effect by shrinking and circularizing the inner cavity, which brings the parking locations of planets closer to the central binary. This work demonstrates the importance of considering both gas and dust in studies of circumbinary discs and planets, and provides a potential means of explaining the orbital properties of circumbinary planets such as Kepler-34b, which have hitherto been difficult to explain using gas-only hydrodynamical simulations.
The northern cross fast radio burst project – II. Monitoring of repeating FRB 20180916B, 20181030A, 20200120E, and 20201124A
Authors: Trudu M , Pilia M , Bernardi G , Addis A , Bianchi G , Magro A , Naldi G , Pelliciari D , Pupillo G , Setti G , Bortolotti C , Casentini C , Dallacasa D , Gajjar V , Locatelli N , Lulli R , Maccaferri G , Mattana A , Michilli D , Perini F , Possenti A , Roma M , Schiaffino M , Tavani M , Verrecchia F 
Published: April 2022

ABSTRACT
In this work, we report the results of a 19-month fast radio burst observational campaign carried out with the north–south arm of the Medicina Northern Cross radio telescope at 408 MHz in which we monitored four repeating sources: FRB20180916B, FRB20181030A, FRB20200120E, and FRB20201124A. We present the current state of the instrument and the detection and characterization of three bursts from FRB20180916B. Given our observing time, our detections are consistent with the event number we expect from the known burst rate (2.7 ± 1.9 above our 10σ, 38 Jy ms detection threshold) in the 5.2 d active window of the source, further confirming the source periodicity. We detect no bursts from the other sources. We turn this result into a 95 per cent confidence level lower limit on the slope of the differential fluence distribution α to be α &gt; 2.1 and α &gt; 2.2 for FRB20181030A and FRB20200120E, respectively. Given the known rate for FRB20201124A, we expect 1.0 ± 1.1 bursts from our campaign, consistent with our non-detection.
Using AGN light curves to map accretion disc temperature fluctuations
Authors: Neustadt J M M , Kochanek C S 
Published: April 2022

ABSTRACT
We introduce a new model for understanding AGN continuum variability. We start from a Shakura–Sunyaev thin accretion disc with a steady-state radial temperature profile T(R) and assume that the variable flux is due to axisymmetric temperature perturbations δT(R, t). After linearizing the equations, we fit UV–optical AGN light curves to determine δT(R, t) for a sample of seven AGNs. We see a diversity of |δT/T| ∼ 0.1 fluctuation patterns which are not dominated by outgoing waves travelling at the speed of light as expected for the ‘lamppost’ model used to interpret disc reverberation mapping studies. Rather, the most common pattern resembles slow (v ≪ c) ingoing waves. An explanation for our findings is that these ingoing waves trigger central temperature fluctuations that act as a lamppost, producing lower amplitude temperature fluctuations moving outwards at the speed of light. The light curves are dominated by the lamppost signal – even though the temperature fluctuations are dominated by other structures with similar variability time-scales – because the discs exponentially smooth the contributions from the slower moving (v ≪ c) fluctuations to the observed light curves. This leads to light curves that closely resemble the expectations for a lamppost model but with the slow variability time-scales of the ingoing waves. This also implies that longer time-scale variability signals will increasingly diverge from lamppost models because the smoothing of slower moving waves steadily decreases as their period or spatial wavelength increases.
Fundamental differences in the properties of red and blue quasars: measuring the reddening and accretion properties with X-shooter
Authors: Fawcett V A , Alexander D M , Rosario D J , Klindt L , Lusso E , Morabito L K , Calistro Rivera G 
Published: April 2022

ABSTRACT
We have recently found fundamental differences in the radio properties of red quasars when compared to typical blue quasars. In this paper, we use data from the X-shooter spectrograph on the Very Large Telescope, providing spectral coverage from ∼3000–$25\,000\,$ Å, of a sample of 40 red and blue luminous quasars at 1.45 &lt; z &lt; 1.65 to explore the connections between the radio, emission-line, and accretion-disc properties. We fit various dust-extinction curves to the data and find that dust reddening can fully explain the observed colours for the majority of the red quasars in our sample, with moderate extinctions ranging from AV ∼ 0.06–0.7 mag. We confront our spectra with a simple thin accretion-disc model and find this can describe the continua of both the blue and red quasars, once corrected for dust extinction; we also find no significant differences in the accretion properties. We detect ionized outflows in a number of red and blue quasars, but do not find any significant evidence that they are more prevalent in the red quasar population. Overall our findings imply that the radio emission is more closely connected to circumnuclear/ISM opacity rather than accretion disc or outflow differences.
Machine learning for fast transients for the Deeper, Wider, Faster programme with the Removal Of BOgus Transients (ROBOT) pipeline
Authors: Goode Simon , Cooke Jeff , Zhang Jielai , Mahabal Ashish , Webb Sara , Hegarty Sarah 
Published: April 2022

ABSTRACTThe Deeper, Wider, Faster (DWF) programme is optimized to detect fast transients that show luminosity changes on time-scales of sub-second to days using fast cadence simultaneous observations and rapid response follow up. One of the significant bottlenecks in DWF is the time required to assess candidates for rapid follow up and to manually inspect candidates prior to triggering space-based or large ground-based telescopes. In this paper, we present the Removal Of BOgus Transients (ROBOTs) pipeline that uses a combination of machine learning methods, a Convolutional Neural Network (CNN), and Decision Tree (CART), to analyse source quality and to filter in promising candidates. The ROBOT pipeline is optimized for ‘lossy’ compressed data required by DWF for fast data transfer to find these candidates within minutes of the light hitting the telescopes. Preliminary testing of the ROBOT pipeline on archival data showed to reduce the number of candidates that require a manual inspection from 69 628 to 3327 (a factor of ∼21 times), whilst simultaneously sorting candidates into categories of priority, with potential for further improvement. Recent real-time operation of the ROBOT pipeline in DWF-O10 showed to further reduce manual inspections from ∼155 000 to ∼5000 (a factor of ∼31 times).
High-density disc reflection spectroscopy of low-mass active galactic nuclei
Authors: Mallick L , Fabian A C , García J A , Tomsick J A , Parker M L , Dauser T , Wilkins D R , De Marco B , Steiner J F , Connors R M T , Mastroserio G , Markowitz A G , Pinto C , Alston W N , Lohfink A M , Gandhi P 
Published: April 2022

ABSTRACTThe standard alpha-disc model predicts an anticorrelation between the density of the inner accretion disc and the black hole mass times square of the accretion rate, as seen in higher mass (MBH &gt; 106 M⊙) active galactic nuclei (AGNs). In this work, we test the predictions of the alpha-disc model and study the properties of the inner accretion flow for the low-mass end (MBH ≈ 105–6 M⊙) of AGNs. We utilize a new high-density disc reflection model where the density parameter varies from ne = 1015 to 1020 cm−3 and apply it to the broad-band X-ray (0.3–10 keV) spectra of the low-mass AGN sample. The sources span a wide range of Eddington fractions and are consistent with being sub-Eddington or near-Eddington. The X-ray spectra reveal a soft X-ray excess below ∼1.5 keV which is well modelled by high-density reflection from an ionized accretion disc of density ne ∼ 1018 cm−3 on average. The results suggest a radiation pressure-dominated disc with an average of 70 per cent fraction of the disc power transferred to the corona, consistent with that observed in higher mass AGNs. We show that the disc density higher than 1015 cm−3 can result from the radiation pressure compression when the disc surface does not hold a strong magnetic pressure gradient. We find tentative evidence for a drop in black hole spin at low-mass regimes.
Mitochondrial 1555 G&gt;A variant as a potential risk factor for childhood glioblastoma
Authors: Li Shaobo , Gai Xiaowu , Myint Swe Swe , Arroyo Katti , Morimoto Libby , Metayer Catherine , de Smith Adam J , Walsh Kyle M , Wiemels Joseph L 
Published: April 2022

Abstract

Background
Childhood glioblastoma multiforme (GBM) is a highly aggressive disease with low survival, and its etiology, especially concerning germline genetic risk, is poorly understood. Mitochondria play a key role in putative tumorigenic processes relating to cellular oxidative metabolism, and mitochondrial DNA variants were not previously assessed for association with pediatric brain tumor risk.

Methods
We conducted an analysis of 675 mitochondrial DNA variants in 90 childhood GBM cases and 2789 controls to identify enrichment of mitochondrial variant associated with GBM risk. We also performed this analysis for other glioma subtypes including pilocytic astrocytoma. Nuclear-encoded mitochondrial gene variants were also analyzed.

Results
We identified m1555 A&gt;G was significantly associated with GBM risk (adjusted OR 29.30, 95% CI 5.25–163.4, P-value 9.5 X 10–4). No association was detected for other subtypes. Haplotype analysis further supported the independent risk contributed by m1555 G&gt;A, instead of a haplogroup joint effect. Nuclear-encoded mitochondrial gene variants identified significant associations in European (rs62036057 in WWOX, adjusted OR = 2.99, 95% CI 1.88–4.75, P-value = 3.42 X 10–6) and Hispanic (rs111709726 in EFHD1, adjusted OR = 3.57, 95% CI 1.99–6.40, P-value = 1.41 X 10–6) populations in ethnicity-stratified analyses.

Conclusion
We report for the first time a potential role played by a functional mitochondrial ribosomal RNA variant in childhood GBM risk, and a potential role for both mitochondrial and nuclear-mitochondrial DNA polymorphisms in GBM tumorigenesis. These data implicate cellular oxidative metabolic capacity as a contributor to the etiology of pediatric glioblastoma.
Synthetic extracellular matrices and astrocytes provide a supportive microenvironment for the cultivation and investigation of primary pediatric gliomas
Authors: Rota Christopher M , Brown Alexander T , Addleson Emily , Ives Clara , Trumper Ella , Pelton Kristine , Teh Wei Pin , Schniederjan Matthew J , Castellino Robert Craig , Buhrlage Sara , Lauffenburger Douglas A , Ligon Keith L , Griffith Linda G , Segal Rosalind A 
Published: April 2022

Abstract

Background
Pediatric gliomas comprise a diverse set of brain tumor entities that have substantial long-term ramifications for patient survival and quality of life. However, the study of these tumors is currently limited due to a lack of authentic models. Additionally, many aspects of pediatric brain tumor biology, such as tumor cell invasiveness, have been difficult to study with currently available tools. To address these issues, we developed a synthetic extracellular matrix (sECM)-based culture system to grow and study primary pediatric brain tumor cells.

Methods
We developed a brain-like sECM material as a supportive scaffold for the culture of primary, patient-derived pediatric glioma cells and established patient-derived cell lines. Primary juvenile brainstem-derived murine astrocytes were used as a feeder layer to support the growth of primary human tumor cells.

Results
We found that our culture system facilitated the proliferation of various primary pediatric brain tumors, including low-grade gliomas, and enabled ex vivo testing of investigational therapeutics. Additionally, we found that tuning this sECM material allowed us to assess high-grade pediatric glioma cell invasion and evaluate therapeutic interventions targeting invasive behavior.

Conclusion
Our sECM culture platform provides a multipurpose tool for pediatric brain tumor researchers that enables both a wide breadth of biological assays and the cultivation of diverse tumor types.
Phase II study of intravenous etoposide in patients with relapsed ependymoma (CNS 2001 04)
Authors: Apps John R , Maycock Shanna , Ellison David W , Jaspan Timothy , Ritzmann Timothy A , Macarthur Donald , Mallucci Conor , Wheatley Keith , Veal Gareth J , Grundy Richard G , Picton Susan 
Published: April 2022

Abstract

Background
Relapsed ependymoma has a dismal prognosis, and the role of chemotherapy at relapse remains unclear. This study prospectively evaluated the efficacy of intensive intravenous (IV) etoposide in patients less than 21 years of age with relapsed intracranial ependymoma (NCT00278252).

Methods
This was a single-arm, open-label, phase II trial using Gehan’s two-stage design. Patients received IV etoposide 100 mg/m2 on days 1-3, 8-10, and 15-17 of each 28-day cycle, up to maximum of 6 cycles. Primary outcome was radiological response after 3 cycles. Pharmacokinetic analysis was performed in 10 patients.

Results
Twenty-five patients were enrolled and included in the intention-to-treat (ITT) analysis. Three patients were excluded in per-protocol (PP) analysis. After 3 cycles of etoposide, 5 patients (ITT 20%/PP 23%) had a complete response (CR), partial response (PR), or objective response (OR). Nine patients (ITT 36%/PP 41%,) had a best overall response of CR, PR, or OR. 1-year PFS was 24% in ITT and 23% in PP populations. 1-year OS was 56% and 59%, 5-year OS was 20% and 18%, respectively, in ITT and PP populations. Toxicity was predominantly hematological, with 20/25 patients experiencing a grade 3 or higher hematological adverse event.

Conclusions
This study confirms the activity of IV etoposide against relapsed ependymoma, however, this is modest, not sustained, and similar to that with oral etoposide, albeit with increased toxicity. These results confirm the dismal prognosis of this disease, provide a rationale to include etoposide within drug combinations, and highlight the need to develop novel treatments for recurrent ependymoma.
The allosteric gating mechanism of the MthK channel
Authors: Guan Fenghui , Li Tianyu , Dong Wei , Guo Rui , Chai Hao , Chen Zhiqiu , Ren Zhong , Li Yang , Ye Sheng 
Published: April 2022

Abstract
Allostery is a fundamental element during channel gating in response to an appropriate stimulus by which events occurring at one site are transmitted to distal sites to regulate activity. To address how binding of the first Ca2+ ion at one of the eight chemically identical subunits facilitates the other Ca2+-binding events in MthK, a Ca2+-gated K+ channel containing a conserved ligand-binding RCK domain, we analysed a large collection of MthK structures and performed the corresponding thermodynamic and electrophysiological measurements. These structural and functional studies led us to conclude that the conformations of the Ca2+-binding sites alternate between two quaternary states and exhibit significant differences in Ca2+ affinity. We further propose an allosteric model of the MthK-gating mechanism by which a cascade of structural events connect the initial Ca2+-binding to the final changes of the ring structure that open the ion-conduction pore. This mechanical model reveals the exquisite design that achieves the allosteric gating and could be of general relevance for the action of other ligand-gated ion channels containing the RCK domain.
A Content Analysis of Promotional Features in US Direct-Mail From Advertisements Across Tobacco Products From 2018 to 2020
Authors: Silver Nathan , Rahman Basmah , Folger Shanell , Bertrand Adrian , Khatib Bushraa , Gbenro Macred , Schillo Barbara 
Published: April 2022

AbstractIntroductionDirect-mail advertising is a crucial channel through which tobacco companies deliver price incentives that lower the barrier to tobacco use while promoting tobacco products via thematic appeals not legally permitted on other marketing channels. We examine the prevalence of price incentives and ad characteristics used in tobacco product advertisements (ads) mailed directly to US consumers.Aims and MethodsWe analyzed the content of direct-mail tobacco ads (N = 1047) in circulation between January 2018 and December 2020 as captured by Mintel Comperemedia Direct. These ads were coded for product type, manufacturer/brand type, model characteristics, price incentives, and themes known to appeal to vulnerable subgroups.ResultsAds across all tobacco products included price incentives (96%) and contained themes that appealed to rural white (40%) and black audiences (15%). Themes known to appeal to youth and young adults were present in 40% of ads across all products, including 78% of ads promoting electronic nicotine delivery systems (ENDS). Moreover, the ENDS ads featuring youth appealing themes (51%), also featured young models.DiscussionExpanding on previous research which focused on combustible and smokeless tobacco products, this analysis examines direct-mail ads across the full range of tobacco products. Our findings highlight the need for regulations to address (1) the high prevalence of price incentives that undermine the effectiveness of excise taxes on tobacco use, and (2) ad themes and characteristics that appeal to groups vulnerable to tobacco use, both of which have the potential to further exacerbate tobacco-related health disparities.ImplicationsThis study reinforces the importance of examining direct-mail as the dominant medium for tobacco advertising, particularly by including coupons and discount codes that reduce product price and thus circumventing the effect of tobacco-related tax legislation. Direct-mail encourages continued product loyalty and use and engages new consumers using price incentives and advertising strategies likely to appeal to price-sensitive consumers and other vulnerable populations. Substantial use of youth-appealing elements in ENDS ads contradicts the tobacco industry’s mandate to not appeal to youth, warranting highlighting the gaps in current regulations that allows them to continue appealing to this population.
The Consequences of the Coronavirus Disease 2019 Pandemic on Smoking Behavior: Evidence from the English Longitudinal Study of Ageing
Authors: Gaggero Alessio 
Published: April 2022

Abstract

Introduction
Smoking is a risk factor for the progression of COVID-19, with smokers having higher odds of COVID-19 progression than never-smokers. This study presents novel findings on the effect of the COVID-19 pandemic on smoking behavior in older adults.

Methods
Panel data were obtained from the English Longitudinal Study of Ageing (N = 60160, 12% smokers, 55% women, 62% married, mean age = 67 years, 23% employed). Fixed-effect regression models were used to estimate the extent to which the COVID-19 pandemic affected smoking behavior. A separate model was estimated for men, women, employed, and retired.

Results
The findings suggest a significant and positive effect of the COVID-19 pandemic on smoking behavior (β = 0.024; P &lt; .001). The estimated effects were stronger for men and for the sample of individuals reporting being employed.

Conclusions
In this study, I provide robust evidence of the effect of the COVID-19 pandemic on smoking behavior using the English Longitudinal Study of Ageing. This large and representative dataset is uniquely suited for the analysis. I find evidence that the proportion of smokers has increased significantly as a result of the COVID-19 pandemic.

Implications
In the United Kingdom, the proportion of smokers increased significantly as a consequence of the COVID-19 pandemic. These findings suggest that smoking behavior may have been used as a mechanism to cope with depression, stress, and anxiety due to the COVID-19 outbreak. To the extent to which smoking behavior has been used as a coping mechanism to deal with job-related issues, targeted policy action to provide financial stability to those in worse economic situations may have beneficial effects on smoking behavior.