bluuebunny/crossref_metadata_2025_split huggingface dataset:
The importance of magnetic fields for the initial mass function of the first stars
Authors: Sharda Piyush , Federrath Christoph , Krumholz Mark R 
Published: July 2020

ABSTRACT
Magnetic fields play an important role for the formation of stars in both local and high-redshift galaxies. Recent studies of dynamo amplification in the first dark matter haloes suggest that significant magnetic fields were likely present during the formation of the first stars in the Universe at redshifts of 15 and above. In this work, we study how these magnetic fields potentially impact the initial mass function (IMF) of the first stars. We perform 200 high-resolution, three-dimensional (3D), magnetohydrodynamic (MHD) simulations of the collapse of primordial clouds with different initial turbulent magnetic field strengths as predicted from turbulent dynamo theory in the early Universe, forming more than 1100 first stars in total. We detect a strong statistical signature of suppressed fragmentation in the presence of strong magnetic fields, leading to a dramatic reduction in the number of first stars with masses low enough that they might be expected to survive to the present-day. Additionally, strong fields shift the transition point where stars go from being mostly single to mostly multiple to higher masses. However, irrespective of the field strength, individual simulations are highly chaotic, show different levels of fragmentation and clustering, and the outcome depends on the exact realization of the turbulence in the primordial clouds. While these are still idealized simulations that do not start from cosmological initial conditions, our work shows that magnetic fields play a key role for the primordial IMF, potentially even more so than for the present-day IMF.
Relaxation of viscoelastic tumblers with application to 1I/2017 (‘Oumuamua) and 4179 Toutatis
Authors: Kwiecinski James A 
Published: July 2020

ABSTRACT
Motivated by the observation of comets and asteroids rotating in non-principal axis (NPA) states, we investigate the relaxation of a freely precessing triaxial ellipsoidal rotator towards its lowest energy spin state. Relaxation of the precession arises from internal dissipative stresses generated by self-gravitation and inertial forces from spin. We develop a general theory to determine the viscoelastic stresses in the rotator, under any linear rheology, for both long-axis (LAM) and short-axis (SAM) modes. By the methods of continuum mechanics, we calculate the power dissipated by the stress field and the viscoelastic material strain, which enables us to determine the time-scale of the precession dampening. To illustrate how the theory is used, we apply our framework to a triaxial 1I/2017 (‘Oumuamua) and 4179 Toutatis under the Maxwell regime. For the former, employing viscoelastic parameters typical of very cold monolithic asteroids renders a dampening time-scale longer by a factor of 1010 and higher than the time-scales found in the works relying on the $\, Q$-factor approach, while the latter yields a time-scale shorter by 107 as a consequence of including self-gravitation. We further reduce our triaxial theory to bodies of an oblate geometry and derive a family of relatively simple analytic approximations determining the NPA dampening times for Maxwell rotators, as well as a criterion determining whether self-gravitation is negligible in the relaxation process. Our approximations exhibit a relative error no larger than $0.2{{\ \rm per\ cent}}$, when compared to numerical integration, for close to non-dissipative bodies and $0.003{{\ \rm per\ cent}}$ for moderately to highly energy dissipating rotators.
Coupling of dual mass-transferring white dwarf binaries as a variable gravitational-wave emitter
Authors: Seto Naoki 
Published: July 2020

ABSTRACT
We study evolution of a hierarchical four-body (2 + 2) system composed by a pair of mass-transferring white dwarf binaries. Applying a simplified model around the synchronous state of two inner orbital periods, we newly find that the four-body system could settle down to a limit cycle with a small period gap. The period gap generates an amplitude variation of emitted gravitational waves as a beat effect. Depending on model parameters, the beat period could be 1–10 yr and a large amplitude variation might be observed by space gravitational-wave detectors.
Perturbation theory approach to predict the covariance matrices of the galaxy power spectrum and bispectrum in redshift space
Authors: Sugiyama Naonori S , Saito Shun , Beutler Florian , Seo Hee-Jong 
Published: July 2020

ABSTRACT
In this paper, we predict the covariance matrices of both the power spectrum and the bispectrum, including full non-Gaussian contributions, redshift space distortions, linear bias effects, and shot-noise corrections, using perturbation theory (PT). To quantify the redshift-space distortion effect, we focus mainly on the monopole and quadrupole components of both the power and bispectra. We, for the first time, compute the 5- and 6-point spectra to predict the cross-covariance between the power and bispectra, and the autocovariance of the bispectrum in redshift space. We test the validity of our calculations by comparing them with the covariance matrices measured from the MultiDark-Patchy mock catalogues that are designed to reproduce the galaxy clustering measured from the Baryon Oscillation Spectroscopic Survey Data Release 12. We argue that the simple, leading-order PT works because the shot-noise corrections for the Patchy mocks are more dominant than other higher order terms we ignore. In the meantime, we confirm some discrepancies in the comparison, especially of the cross-covariance. We discuss potential sources of such discrepancies. We also show that our PT model reproduces well the cumulative signal-to-noise ratio of the power spectrum and the bispectrum as a function of maximum wavenumber, implying that our PT model captures successfully essential contributions to the covariance matrices.
On the seismic emission in sunspots associated with Lorentz force changes accompanying major solar flares
Authors: Kumar Hirdesh , Kumar Brajesh 
Published: July 2020

ABSTRACT
Solar flares are known to generate seismic waves in the Sun. We present a detailed analysis of seismic emission in sunspots accompanying M- and X-class solar flares. For this purpose, we have used high-resolution Dopplergrams and line-of-sight magnetograms at a cadence of 45 s, along with vector magnetograms at a cadence of 135 s obtained from Helioseismic and Magnetic Imager instrument aboard the Solar Dynamics Observatory space mission. In order to identify the location of flare ribbons and hard X-ray footpoints, we have also used Hα chromospheric intensity observations obtained from Global Oscillation Network Group instruments and hard X-ray images in 12–25 keV band from the Reuvan Ramaty High Energy Solar Spectroscopic Imager spacecraft. The fast Fourier transform technique is applied to construct the acoustic velocity power map in 2.5–4 mHz band for pre-flare, spanning flare, and post-flare epochs for the identification of seismic emission locations in the sunspots. In the power maps, we have selected only those locations which are away from the flare ribbons and hard X-ray footpoints. These regions are believed to be free from any flare related artefacts in the observational data. We have identified concentrated locations of acoustic power enhancements in sunspots accompanying major flares. Our investigation provides evidence that abrupt changes in the magnetic fields and associated impulsive changes in the Lorentz force could be the driving source for these seismic emissions in the sunspots during solar flares.
The RNA exosome shapes the expression of key protein-coding genes
Authors: Wu Mengjun , Karadoulama Evdoxia , Lloret-Llinares Marta , Rouviere Jerome Olivier , Vaagensø Christian Skov , Moravec Martin , Li Bingnan , Wang Jingwen , Wu Guifen , Gockert Maria , Pelechano Vicent , Jensen Torben Heick , Sandelin Albin 
Published: July 2020

Abstract
The ribonucleolytic exosome complex is central for nuclear RNA degradation, primarily targeting non-coding RNAs. Still, the nuclear exosome could have protein-coding (pc) gene-specific regulatory activities. By depleting an exosome core component, or components of exosome adaptor complexes, we identify ∼2900 transcription start sites (TSSs) from within pc genes that produce exosome-sensitive transcripts. At least 1000 of these overlap with annotated mRNA TSSs and a considerable portion of their transcripts share the annotated mRNA 3′ end. We identify two types of pc-genes, both employing a single, annotated TSS across cells, but the first type primarily produces full-length, exosome-sensitive transcripts, whereas the second primarily produces prematurely terminated transcripts. Genes within the former type often belong to immediate early response transcription factors, while genes within the latter are likely transcribed as a consequence of their proximity to upstream TSSs on the opposite strand. Conversely, when genes have multiple active TSSs, alternative TSSs that produce exosome-sensitive transcripts typically do not contribute substantially to overall gene expression, and most such transcripts are prematurely terminated. Our results display a complex landscape of sense transcription within pc-genes and imply a direct role for nuclear RNA turnover in the regulation of a subset of pc-genes.
Microstructures and Late-Stage Magmatic Processes in Layered Mafic Intrusions: Symplectites from the Sept Iles Intrusion, Quebec, Canada
Authors: Keevil Halley A , Namur Olivier , Holness Marian B 
Published: July 2020

AbstractReplacive symplectites (vermicular intergrowths of two or more minerals) are an important feature of layered igneous intrusions, recording evidence of late-stage reactions between interstitial liquid and crystals. They are common throughout the Layered Series of the 564 Ma Sept Iles layered intrusion in Quebec, Canada, and fall into three types: oxy-symplectites, ‘Type I’ symplectites, and ‘Type II’ symplectites. Oxy-symplectites are comprised of magnetite and orthopyroxene, nucleate on olivine primocrysts, and form via the reaction Olivine + O2 → Orthopyroxene + Magnetite; Type I symplectites (of which there are 3 distinct categories) are comprised of anorthitic plagioclase with pyroxene, amphibole, or olivine vermicules, grow from primocryst oxide grains, and replace primocryst plagioclase; and Type II symplectites (of which there are 2 distinct categories) are comprised of anorthitic plagioclase with orthopyroxene ± amphibole vermicules, grow from primocryst olivine grains, and replace primocryst plagioclase. Rare symplectites composed of biotite and plagioclase are also present. Symplectite growth occurred at 700–1030°C with pressure constraints of 1–2 kbar. We propose that Type I symplectites, and some Type II symplectites, formed from the interaction of primocrysts with residual Fe-rich liquid as a consequence of differential loss of an immiscible Si-rich liquid conjugate from the crystal mush. However, redistribution and concentration of hydrous fluids in incompletely solidified rock, or an increase in water activity of the interstitial melt, may be more plausible processes responsible for the formation of replacive symplectites comprising abundant hydrous mineral assemblages.
Lymphoma risks in patients with rheumatoid arthritis treated with biological drugs—a Swedish cohort study of risks by time, drug and lymphoma subtype
Authors: Hellgren Karin , Di Giuseppe Daniela , Smedby Karin E , Sundström Christer , Askling Johan , Baecklund Eva ,   for the ARTIS study group
Published: July 2020

Abstract

Objectives
To estimate the association between biological DMARDs (bDMARDs; overall and by drug) as used in RA and the risk of malignant lymphomas including subtypes.

Methods
By linking nationwide Swedish registers we identified cohorts of patients with RA initiating treatment with a bDMARD (n = 16 392), bDMARD-naïve (n = 55 253), an age- and sex-matched general population comparator cohort (n = 229 047), and all incident lymphomas 2001–16. We used Cox regression to calculate hazard ratios (HRs) of lymphoma taking calendar period and other factors into account.

Results
There were 82 lymphomas among the bDMARD-treated patients with RA, crude incidence rate 76/100 000 person-years, and 310 lymphomas among the bDMARD-naïve patients with RA, crude incidence rate 90/100 000 person-years. This resulted in an adjusted HR (aHR) associated with bDMARD treatment (vs not) of 1.08 (95% CI: 0.83, 1.41). The corresponding aHR for bDMARD-treated and bDMARD-naïve vs the general population was 1.65 (95% CI: 1.31, 2.08) and 1.56 (95% CI: 1.37, 1.78) respectively. Restricting follow-up period to after 2006, the aHR of lymphoma for patients with RA starting a first bDMARD vs bDMARD-naïve was 0.69 (95% CI: 0.47, 1.00), and for bDMARD treated vs patients with RA switching from one conventional synthetic DMARDs to another, aHR was 0.46 (95% CI: 0.28, 0.73). There were no signals of different risks with any particular TNF inhibitor (TNFi) agent. We found no different lymphoma subtype pattern following bDMARD therapy.

Conclusion
Treatment with bDMARDs, including both TNFi and non-TNFi bDMARDs, does not further increase the lymphoma risk in RA; instead, bDMARD treatment may actually reduce the excess lymphoma risk in RA.
Treatment strategies in axial spondyloarthritis: what, when and how?
Authors: Fragoulis George E , Siebert Stefan 
Published: July 2020

Abstract
There have been major advances in the management of axial spondyloarthritis (axSpA) with the introduction of effective biologic agents targeting TNF and IL-17A. Clinicians now have more choice but, despite treatment recommendations, are still faced with significant uncertainty when deciding on the optimal treatment strategy for an individual patient in clinical practice. Management of axSpA typically requires both non-pharmacological and pharmacological interventions. NSAIDs remain the first line drug therapies for axSpA with proven efficacy for symptomatic management but uncertainty remains regarding their optimal long-term use relating to radiographic progression and safety in axSpA. To-date there are no head-to-head trials of biologics in axSpA. Clinicians need to consider other factors, including extra-articular manifestations, comorbidities, safety and radiographic progression when deciding on which biologic to recommend for an individual patient. This article will explore the evidence relating to these factors and highlight areas of unmet need.
Variegated financialization and pension fund asset demand: the case of Colombia and Perú
Authors: Bonizzi Bruno , Churchill Jennifer , Guevara Diego 
Published: July 2020

AbstractThis article seeks to explain concretely how one ‘variegation’ of financialization in the emerging economy setting is being shaped by the growth of domestic pension funds. Taking Colombia and Perú as case studies, we explore the evolution of pension fund demand subsequent to substantial pension policy reforms in the 1990s. Drawing on comparative political economy and the recent literature on subordinate financialization in emerging economies, we present a three-tiered conjecture regarding what is shaping pension fund demand: (a) the particular institutional context of ‘hierarchical market economies’ and neoliberal market reforms, (b) the ‘extraverted’ growth regime and (c) subordinate financial integration. The resulting demand calls forth financial innovation and movement towards market-based financial mechanisms as seen with financialization elsewhere, yet in this instance occurring largely outside of domestic capital markets.
Cognitive effects of split and continuous sleep schedules in adolescents differ according to total sleep opportunity
Authors: Lo June C , Leong Ruth L F , Ng Alyssa S C , Jamaluddin S Azrin , Ong Ju Lynn , Ghorbani Shohreh , Lau TeYang , Chee Nicholas I Y N , Gooley Joshua J , Chee Michael W L 
Published: July 2020

Abstract

Study Objectives
We compared the basic cognitive functions of adolescents undergoing split (nocturnal sleep + daytime nap) and continuous nocturnal sleep schedules when total sleep opportunity was either below or within the recommended range (i.e. 6.5 or 8 h).

Methods
Adolescent participants (age: 15–19 year) in the 8-h split (n = 24) and continuous (n = 29) sleep groups were compared with 6.5-h split and continuous sleep groups from a previous study (n = 58). These protocols involved two baseline nights (9-h time-in-bed [TIB]), 5 nights of sleep manipulation, 2 recovery nights (9-h TIB), followed by a second cycle of sleep manipulation (3 nights) and recovery (2 nights). Cognitive performance, subjective sleepiness, and mood were evaluated daily; sleep was assessed using polysomnography.

Results
Splitting 6.5 h of sleep with a mid-afternoon nap offered a boost to cognitive function compared to continuous nocturnal sleep. However, when total TIB across 24 h increased to 8 h, the split and continuous sleep groups performed comparably in tests evaluating vigilance, working memory, executive function, processing speed, subjective sleepiness, and mood.

Conclusions
In adolescents, the effects of split sleep on basic cognitive functions vary by the amount of total sleep obtained. As long as the total sleep opportunity across 24 h is within the recommended range, students may fulfill sleep requirements by adopting a split sleep schedule consisting of a shorter period of nocturnal sleep combined with a mid-afternoon nap, without significant impact on basic cognitive functions.

Clinical trial registration
NCT04044885.
Three myeloproliferative neoplasms
Authors: Brennan-Cook Jill 
Published: July 2020

Abstract:
A group of rare hematologic cancers, myeloproliferative neoplasms (MPNs) evolve when bone marrow dysfunction causes overproduction of one or more blood cell types. This article explores the diagnosis, treatment, and nursing care of patients diagnosed with one of three classic MPNs: essential thrombocythemia, polycythemia vera, and primary myelofibrosis.
Immediate postoperative high-sensitivity troponin T concentrations and long-term patient-reported health-related quality of life
Authors: Mol Kristin H.J.M. , van Lier Felix , Liem Victor G.B. , Stolker Robert J. , Hoeks Sanne E. 
Published: July 2020

BACKGROUND
Myocardial injury after noncardiac surgery is associated with mortality and major adverse postoperative cardiovascular events. The effect of postoperative troponin concentrations on patient-reported health-related quality of life (HRQoL) is unknown.

OBJECTIVE
The study examined the association between immediate postoperative troponin concentrations and self-reported HRQoL 1 year after surgery.

DESIGN
Prospective cohort study.

SETTING
Single-centre tertiary care hospital in the Netherlands between July 2012 and 2015.

PATIENTS
Patients aged at least 60 years undergoing moderate and major noncardiac surgery.

INTERVENTION
None.

MAIN OUTCOME MEASURES
HRQoL total score was assessed with the EuroQol five-dimensional questionnaire. Tobit regression analysis was used to determine the association between postoperative troponin concentrations and 1-year HRQoL. Peak high-sensitivity troponin T values were divided into four categories: less than 14, 14 to 49, 50 to 149 and at least 150 ng l−1.

RESULTS
A total of 3085 patients with troponin measurements were included. 2634 (85.4%) patients were alive at 1-year follow-up of whom 1297 (49.2%) returned a completed questionnaire. The median score for HRQoL was 0.82 (0.85, 0.81, 0.77 and 0.71 per increasing troponin category). Multivariable analysis revealed betas of −0.06 [95% confidence interval (CI) −0.09 to −0.02], −0.11 (95% CI −0.18 to −0.04) and −0.18 (95% CI −0.29 to −0.07) for troponin levels of 14 to 49, 50 to 149 and at least 150 ng l−1 when compared with values less than 14 ng l−1. Other independent predictors for lower HRQoL were chronic obstructive pulmonary disease, female sex, peripheral arterial disease and increasing age.

CONCLUSION
Higher levels of postoperative troponin measured immediately after surgery were independently associated with lower self-reported HRQoL total score at 1-year follow-up.
Apolipoprotein E ε4 and cognitive function after surgery in middle-aged and elderly Danish twins
Authors: Dokkedal Unni , Wod Mette , Thinggaard Mikael , Hansen Tom G. , Rasmussen Lars S. , Christensen Kaare , Mengel-From Jonas 
Published: July 2020

BACKGROUNDTransient cognitive impairment is common in adult patients of all ages following anaesthesia and surgery. Apolipoprotein E (APOE) ε4 carriers may have a larger deterioration in short-term cognitive function after major surgery compared with APOE ε4 noncarriers.OBJECTIVESThe aim was to examine the effect of APOE ε4 on the association between exposure to surgery and anaesthesia, and subsequent cognitive functioning. A more pronounced deterioration in cognitive function in APOE ε4 carriers was hypothesised.DESIGNAn observational cross-sectional and a 6 to 10 years longitudinal twin cohort design.SETTINGSurvey and register study of 2936 Danish twins aged 45 to 92 years.MAIN OUTCOME MEASURESCognitive function was assessed using five age-sensitive cognitive tests. In the cross-sectional study, we compared twins exposed to surgery with a reference group (unexposed). Linear regression models were used adjusting for sex and age and stratified by APOE ε4 carrier status. In the longitudinal cognitive follow-up study 1671 twins participated. Intrapair analyses were also performed using 70 same-sexed twin pairs concordant for APOE ε4 carrier status, but discordant for major surgery.RESULTSAPOE ε4 carriers had lower cognitive scores compared with noncarriers, and this was statistically significant in elderly twins 70+ years of age (mean difference, −0.67; 95% CI, −1.14 to −0.17). There was no significant impact on cognitive function after surgery according to APOE ε4 carrier status in the cross-sectional study. Similarly, there was no APOE ε4 modification in the longitudinal study. Also, in the intrapair analyses no evidence was found of lower cognitive score after major surgery compared with the nonexposed cotwins among APOE ε4 carriers.CONCLUSIONNo evidence was found of more pronounced long-term deterioration in cognitive function after surgery among APOE ε4 carriers, but elderly APOE ε4 carriers in general performed worse on the cognitive tests than noncarriers.
The accuracy of haemoglobin A1c as a screening and diagnostic test for gestational diabetes: a systematic review and meta-analysis of test accuracy studies
Authors: Amaefule Chiamaka Esther , Sasitharan Archana , Kalra Princee , Iliodromoti Stamatina , Huda Mohammed S.B. , Rogozinska Ewelina , Zamora Javier , Thangaratinam Shakila 
Published: July 2020

Purpose of reviewGestational diabetes mellitus (GDM) is associated with adverse pregnancy complications. Accurate screening and diagnosis of gestational diabetes are critical to treatment, and in a pandemic scenario like coronavirus disease 2019 needing a simple test that minimises prolonged hospital stay. We undertook a meta-analysis on the screening and diagnostic accuracy of the haemoglobin A1c (HbA1c) test in women with and without risk factors for gestational diabetes.Recent findingsUnlike the oral glucose tolerance test, the HbA1c test is simple, quick and more acceptable. There is a growing body of evidence on the accuracy of HbA1c as a screening and diagnostic test for GDM. We searched Medline, Embase and Cochrane Library and selected relevant studies. Accuracy data for different thresholds within the final 23 included studies (16 921 women) were pooled using a multiple thresholds model. Summary accuracy indices were estimated by selecting an optimal threshold that optimises either sensitivity or specificity according to different scenarios.SummaryHbA1c is more useful as a specific test at a cut-off of 5.7% (39 mmol/mol) with a false positive rate of 10%, but should be supplemented by a more sensitive test to detect women with GDM.