bluuebunny/crossref_metadata_2025_split huggingface dataset:
A possible model for the long-term flares of Sgr A*
Authors: Okuda Toru , Singh Chandra B , Das Santabrata , Aktar Ramiz , Nandi Anuj , Dal Pino Elisabete M de Gouveia 
Published: February 2019

Abstract
We examine the effects of magnetic field on low angular momentum flows with standing shock around black holes in two dimensions. The magnetic field brings change in behavior and location of the shock which results in regularly or chaotically oscillating phenomena of the flow. Adopting fiducial parameters like specific angular momentum, specific energy, and magnetic field strength for the flow around Sgr A*, we find that the shock moves back and forth in the range 60–$170\, R_{\rm g}$, irregularly recurring with a time-scale of ∼ 5 d with an accompanying, more rapid, small modulation with a period of 25 hr without fading, where Rg is the Schwarzschild radius. The time-variability associated with the two different periods is attributed to the oscillating outer strong shock, together with another rapidly oscillating inner weak shock. As a consequence of the variable shock location, the luminosities vary roughly by more than a factor of 3. The time-dependent behaviors of the flow are well compatible with luminous flares with a frequency of ∼ one per day and bright flares occurring every ∼ 5–10 d in the latest observations by Chandra, Swift, and XMM-Newton monitoring of Sgr A*.
CO Multi-line Imaging of Nearby Galaxies (COMING). III. Dynamical effect on molecular gas density and star formation in the barred spiral galaxy NGC 4303
Authors: Yajima Yoshiyuki , Sorai Kazuo , Kuno Nario , Muraoka Kazuyuki , Miyamoto Yusuke , Kaneko Hiroyuki , Nakanishi Hiroyuki , Nakai Naomasa , Tanaka Takahiro , Sato Yuya , Salak Dragan , Morokuma-Matsui Kana , Matsumoto Naoko , Pan Hsi-An , Noma Yuto , Takeuchi Tsutomu T , Yoda Moe , Kuroda Mayu , Yasuda Atsushi , Oi Nagisa , Shibata Shugo , Seta Masumichi , Watanabe Yoshimasa , Kita Shoichiro , Komatsuzaki Ryusei , Kajikawa Ayumi , Yashima Yu 
Published: February 2019

Abstract
We present the results of $^{12}\textrm{C}$$\textrm{O}$(J = 1–0) and $^{13}\textrm{C}$$\textrm{O}$(J = 1–0) simultaneous mappings toward the nearby barred spiral galaxy NGC 4303 as part of the CO Multi-line Imaging of Nearby Galaxies (COMING) project. Barred spiral galaxies often show lower star-formation efficiency (SFE) in their bar region compared to the spiral arms. In this paper, we examine the relation between the SFEs and the volume densities of molecular gas n(H2) in the eight different regions within the galactic disk with $\textrm{C}$$\textrm{O}$ data combined with archival far-ultraviolet and 24 μm data. We confirmed that SFE in the bar region is lower by 39% than that in the spiral arms. Moreover, velocity-alignment stacking analysis was performed for the spectra in the individual regions. Integrated intensity ratios of $^{12}\textrm{C}$$\textrm{O}$ to $^{13}\textrm{C}$$\textrm{O}$ (R12/13) ranging from 10 to 17 were the results of this stacking. Fixing a kinetic temperature of molecular gas, $n(\rm {H_2})$ was derived from R12/13 via non-local thermodynamic equilibrium (non-LTE) analysis. The density n(H2) in the bar is lower by 31%–37% than that in the arms and there is a rather tight positive correlation between SFEs and n(H2), with a correlation coefficient of ∼0.8. Furthermore, we found a dependence of $n(\rm {H}_2)$ on the velocity dispersion of inter-molecular clouds (ΔV/sin i). Specifically, n(H2) increases as ΔV/sin i increases when ΔV/sin i &lt; 100 km s−1. On the other hand, n(H2) decreases as ΔV/sin i increases when ΔV/sin i &gt; 100 km s−1. These relations indicate that the variations of SFE could be caused by the volume densities of molecular gas, and the volume densities could be governed by the dynamical influence such as cloud–cloud collisions, shear, and enhanced inner-cloud turbulence.
An X-ray spectroscopic search for dark matter and unidentified line signatures in the Perseus cluster with Hitomi
Authors: Tamura Takayuki , Fabian Andrew C , Gandhi Poshak , Gu Liyi , Kamada Ayuki , Kitayama Tetsu , Loewenstein Michael , Maeda Yoshitomo , Matsushita Kyoko , McCammon Dan , Mitsuda Kazuhisa , Nakashima Shinya , Porter Scott , Pinto Ciro , Sato Kosuke , Tombesi Francesco , Yamasaki Noriko Y 
Published: February 2019

AbstractThe reported detection of a 3.5 keV emission signal in the Perseus cluster core by Bulbul et al. (2014, ApJ, 789, 13) was ruled out at high confidence in analysis conducted by Aharonian et al. (2017, ApJ, 837, L15) of X-ray spectra at 5 eV energy resolution obtained with the Hitomi observatory Soft X-ray Spectrometer (SXS). Using the same data, we search the full 2–12 keV SXS energy band for previously unidentified emission and absorption features. No significant unidentified line emission or absorption is found. Line flux upper limits (1σ per resolution element) vary with photon energy and assumed intrinsic width, decreasing from ∼100 at 2 keV to &lt;10 photons cm−2 s−1 sr−1 over most of the 5–10 keV energy range for a Gaussian line with Doppler broadening of 640 km s−1. Limits for narrower and broader lines have a similar energy dependence and are systematically smaller and larger, respectively. These line flux limits are used to constrain the decay rate of hypothetical dark matter candidates. For the sterile neutrino decay rate, we place new constraints over the mass range of 4–24 keV with mass resolution better than any previous X-ray analysis. Additionally, the accuracy of relevant thermal spectral models and atomic data are evaluated. The Perseus cluster spectra may be described by a composite of multi-temperature thermal and active galactic nuclei (AGN) power-law continua. Superposed on these, a few line emission signals possibly originating from unmodeled atomic processes (including Si xiv and Fe xxv) are marginally detected and tabulated. Comparisons with previous X-ray upper limits and future prospects for dark matter searches using high-energy resolution spectroscopy are discussed.
The Effectiveness of Autologous Platelet-Rich Plasma for Osteoarthritis of the Hip: A Retrospective Analysis
Authors: Singh Jaspal Ricky , Haffey Paul , Valimahomed Ali , Gellhorn Alfred C 
Published: February 2019

AbstractBackgroundPlatelet-rich plasma (PRP) is a minimally invasive treatment option to reduce pain and promote tissue healing. At the time this study was performed, there was limited published literature analyzing outcomes for patients treated with PRP for hip osteoarthritis.MethodsThirty-six patients aged 49–85 (66.0 ± 12.1) years with chronic hip pain who met inclusion criteria underwent image-guided intra-articular hip PRP injection. Outcomes were measured at baseline, two weeks, three months, and up to six months using the visual analog scale (VAS) for pain and the Hip Disability and Osteoarthritis Outcome Score (HOOS). The proportion of responders, as defined by a ≥50% reduction in VAS pain score, was assessed at three and six months.ResultsAt two weeks, there was a significant improvement (P < 0.05) of function in two HOOS subscales: Symptoms and Activities of Daily Living. There was a significant improvement in all HOOS categories at six months. A significant improvement in VAS was observed at six months (baseline VAS = 6.9 ± 0.7 &→ 4.3 ± 1.8, 95% confidence interval = 2.0 to 3.2, P < 0.05). Sixty-seven percent (24/36) of the patients reported a ≥50% improvement in pain at three months; 58% (21/36) reported a ≥50% improvement in pain at six months. Stratification by Kellgren-Lawrence grades revealed that 86% and 82% of the KL grades 1 and 2 were responders at six months, respectively.ConclusionsIn patients with mild/moderate hip osteoarthritis, PRP may provide pain relief and functional improvement for up to six months.
Partisanship, Polling, and the Affordable Care Act
Authors: Brodie Mollyann , Hamel Elizabeth C , Kirzinger Ashley , Dijulio Bianca 
Published: February 2019

AbstractIn an age of increasing political polarization, the Affordable Care Act (ACA) stands out as one of the most politically divisive pieces of legislation in recent history. Unlike previous laws making changes to the US health care system, public views of the ACA did not improve measurably as people gained experience with the program, but remained deeply divided on a partisan basis in the more than eight years since its passage. In this article, we examine how the complexity of the law, lack of understanding by the public, and elite partisan messaging have contributed to this enduring partisan divide, and discuss what the future may hold for the measurement of public opinion on major health care legislation.
A re-evaluation of teenage sunbed use following the introduction of banning legislation for under 18-year-olds
Authors: Menzies S , Daly S , O’Connor R , Kelly A , Fitzgerald M , Bourke J , McKenna D B 
Published: February 2019

AbstractBackgroundThere is little information on the effectiveness of introducing age restriction legislation alone to reduce the rate of sunbed usage by teenagers. Prior to the Public Health (Sunbed) Act of 2014 prohibiting the use of sunbeds in under 18-year-olds in Ireland we reported the rate of sunbed use at 7.5%.ObjectivesThe aim of the study was to compare the rate of sunbed usage among Irish teenagers before and after the introduction of banning legislation to determine if it had the desired effect of reducing its rate of use.MethodsIn a cross-sectional survey, students from the same schools as in our previous study completed an anonymous, written questionnaire pertaining to sunbed usage.ResultsIn total, 783 questionnaires, from 13 schools across Ireland, were completed. The rate of sunbed use in the current study was 7.2%, compared to 7.5% in the pre-ban study, (P = 0.76). A higher rate of sunbed use was observed in Dublin schools and female public students.ConclusionOur study suggests that legislation alone is ineffective at reducing sunbed usage in a teenage population. A multifaceted approach is required that includes enforcement of the legislation together with targeted public education and awareness campaigns using all aspects of the media.
Lymphomas complicating primary Sjögren’s syndrome: from autoimmunity to lymphoma
Authors: Nocturne Gaetane , Pontarini Elena , Bombardieri Michele , Mariette Xavier 
Published: February 2019

Abstract
Lymphoma development is the most serious complication of SS and the main factor impacting on mortality rate in patients with this condition. Lymphomas in SS are most commonly extranodal non-Hodgkin B-cell lymphomas of the mucosa-associated lymphoid tissue and frequently arise in salivary glands that are the target of a chronic inflammatory autoimmune process. Extensive work on lymphomagenesis in SS has established that the progression towards B-cell lymphoma is a multistep process related to local chronic antigenic stimulation of B cells. These neoplastic B cells in SS frequently derived from autoreactive clones, most commonly RF-producing B cells, which undergo uncontrolled proliferation and malignant escape. In this review, we highlight the most important recent findings that have enhanced our understanding of lymphoma development in SS, with particular reference to the close link between autoimmunity and lymphomagenesis. We also discuss how the identification of key factors involved in B-cell malignancies may impact on our ability to identify at early stages patients at increased risk of lymphoma with potential significant repercussions for the clinical management of SS patients. Finally, we identified the most promising areas of current and further research with the potential to provide novel basic and translational discoveries in the field. The questions of finding new biomarkers, developing a validated score for predicting lymphoma occurrence and assessing if a better control of disease activity will decrease the risk of lymphoma in primary SS will be the enthralling questions of the next few years.
The autoantibody response to cyclic citrullinated collagen type II peptides in rheumatoid arthritis
Authors: Liang Bibo , Ge Changrong , Lönnblom Erik , Lin Xiaoyin , Feng Hui , Xiao Lianbo , Bai Jing’an , Ayoglu Burcu , Nilsson Peter , Nandakumar Kutty Selva , Zhao Ming , Holmdahl Rikard 
Published: February 2019

Abstract

Objectives
The detection of anti-citrullinated peptide antibodies (ACPAs) is a serological hallmark of RA. Autoantibodies reactive with collagen type II (CII) are present in RA sera and synovial fluid and are potentially pathogenic. Here, we investigate the prevalence and specificity of the autoantibody responses to defined citrullinated cyclic peptides derived from CII in a China RA cohort.

Methods
Using bead-based multiplex assay, we examined the presence of autoantibodies binding to 54 cyclic 17-mer citrullinated CII peptides, encompassing all citrullinate epitopes in CII, and the corresponding unmodified peptides in 415 RA patients, in addition to 304 patients with OA. Furthermore, the autoantibody responses to a selected set of 10 cyclic citrullinated peptides were also examined in 203 healthy individuals.

Results
Autoantibody responses to cyclic citrullinated CII peptides were higher in RA patients as compared with OA patients or healthy individuals, whereas little or negligible antibody responses to cyclic unmodified CII peptides were observed. Interestingly, several novel citrullinated CII epitopes were identified. Antibodies to these novel citrullinated CII epitopes showed not only substantial overlapping reactivities but also had unique specificities.

Conclusion
We found a high prevalence of autoantibodies against cyclic citrullinated CII in the sera of patients in a China RA cohort. The present study revealed heterogeneous binding patterns against novel citrullinated CII epitopes, which may help to stratify RA patients into different subgroups.
Three dimensions of institutional contention: efficiency, equality and governance in Danish vocational education and training reform
Authors: Carstensen Martin B , Ibsen Christian Lyhne 
Published: February 2019

Abstract
This article develops a new analytical framework to account for institutional change in vocational education and training (VET) systems. Trajectories of institutional change are typically explained using one of two perspectives on institutional contention. First, the Varieties of Capitalism-approach highlights positive efficiency effects from coordination between companies on skill formation. Second, a historical institutionalist approach focuses on positive political feedback effects from the governance of VET institutions. We propose adding a third dimension of institutional contention related to what role VET should play in fostering greater socio-economic equality. Employing this three-dimensional framework enables a more fine-grained analysis of gradual forms of institutional change and greater appreciation of the ways in which political struggles over the configuration of the three dimensions drive institutional reform. The argument is supported by analyzing the trajectory of institutional change in the Danish VET system in the post-war period.
Fatherhood, Motherhood and Time Pressure in Australia, Korea, and Finland
Authors: Craig Lyn , Brown Judith E , Jun Jiweon 
Published: February 2019

Abstract
Using nationally representative Time Use Surveys from Australia, Korea, and Finland (n = 19,127 diaries) we examine how parenthood and the age of the youngest child are associated with the recuperative activities of leisure and sleep, the productive activities of market and nonmarket work, and with subjective time stress. Time stress differences by fatherhood are greatest for Finns and least for Koreans; time stress differences by motherhood are absent for Finns and high for Australians and Koreans. Results of the comparative analysis suggest that social policy and average national working hours produce different gendered gaps in both objective and subjective time stress among parents.
Behavior Revealed in Mobile Phone Usage Predicts Credit Repayment
Authors: Björkegren Daniel , Grissen Darrell 
Published: February 2019

Abstract
Many households in developing countries lack formal financial histories, making it difficult for firms to extend credit, and for potential borrowers to receive it. However, many of these households have mobile phones, which generate rich data about behavior. This article shows that behavioral signatures in mobile phone data predict default, using call records matched to repayment outcomes for credit extended by a South American telecom. On a sample of individuals with (thin) financial histories, this article's method actually outperforms models using credit bureau information, both within-time and when tested on a different time period. But the method also attains similar performance on those without financial histories, who cannot be scored using traditional methods. Individuals in the highest quintile of risk by the measure used in this article are 2.8 times more likely to default than those in the lowest quintile. The method forms the basis for new forms of credit that reach the unbanked.
Mesoscale modelling of soft flowing crystals
Authors: Montessori A. , Lauricella M. , Succi S. 
Published: February 2019

We outline the main ideas behind the numerical modelling of soft flowing crystals, paying special attention to their application to microfluidic devices for the design of novel mesoscale porous materials.This article is part of the theme issue ‘Multiscale modelling, simulation and computing: from the desktop to the exascale’.
Multi-scale high-performance computing in astrophysics: simulating clusters with stars, binaries and planets
Authors: van Elteren A. , Bédorf J. , Portegies Zwart S. 
Published: February 2019

The demand on simulation software in astrophysics has dramatically increased over the last decades. This increase is driven by improvements in observational data and computer hardware. At the same time, computers have become more complicated to program due to the introduction of more parallelism and hybrid hardware. To keep up with these developments, much of the software has to be redesigned. In order to prevent the future need to rewrite again when new developments present themselves, the main effort should go into making the software maintainable, flexible and scalable. In this paper, we explain our strategy for coupling elementary solvers and how to combine them into a high-performance multi-scale environment in which complex simulations can be performed. The elementary parts can remain succinct while supporting the aggregation to more satisfactory functionality by coupling them on a higher level. The advanced code-coupling strategies we present here allow such a hierarchy and support the development of complex codes. A library of simple elementary solvers subsequently stimulates the rapid development of more complex code that can co-evolve with the latest advances in computer hardware. We demonstrate how to combine several of these elementary solvers in a hierarchical and generic system, and how the resulting complex codes can be applied to multi-scale problems in astrophysics. Our aim is to achieve the best of several worlds with respect to performance, flexibility and maintainability while reducing development time. We succeeded in the development of the hierarchical coupling strategy and the general framework, but a comprehensive library of minimal fundamental-physics solvers is still unavailable.
This article is part of the theme issue ‘Multiscale modelling, simulation and computing: from the desktop to the exascale’.
Human Retina-on-a-Chip: Merging Organoid and Organ-on-a-Chip Technology to Generate Complex Multi-Layer Tissue Models
Authors: Achberger Kevin , Probst Christopher , Haderspeck Jasmin C. , Bolz Sylvia , Rogal Julia , Chuchuy Johanna , Nikolova Marina , Cora Virginia , Antkowiak Lena , Haq Wadood , Shen Nian , Schenke-Layland Katja , Ueffing Marius , Liebau Stefan , Loskill Peter 
Published: February 2019

AbstractThe devastating effects and incurable nature of hereditary and sporadic retinal diseases such as Stargardt disease, age-related macular degeneration or retinitis pigmentosa urgently require the development of new therapeutic strategies. Additionally, the prevalence of retinal toxicities is becoming more and more an issue of novel targeted therapeutic agents. To date, (ophthalmologic) drug development largely relies on animal models. Inadequate translatability of results from animal models to humans, however, limits advances in drug development and discovery. Hence, the establishment of more relevant human tissue-based in vitro models is of upmost importance. The discovery of self-forming retinal organoids (ROs) derived from human embryonic stem cells (hESCs) or human induced pluripotent stem cells (hiPSCs) is a promising approach to model the complex stratified retinal tissue. Yet, ROs lack vascularization and cannot recapitulate the important physiological interactions of matured photoreceptors and the retinal pigment epithelium (RPE). In this study, we present the retina-on-a-chip (RoC), a novel microphysiological model of the human retina integrating more than seven different essential retinal cell types derived from hiPSCs in a vasculature-like perfusion and enabling, for the first time, the recapitulation of the interaction of mature photoreceptor segments with RPE in vitro. We show that this interaction enhances the formation of outer segment like-structures and the establishment of in vivo-like physiological processes such as outer segment phagocytosis and calcium dynamics. In addition, we demonstrate the applicability of the RoC for drug testing, by reproducing the retinopathic side effects of the anti-malaria drug chloroquine and the antibiotic gentamicin. The developed hiPSC-based RoC has the potential to promote drug development and provide new insights into the underlying pathology of retinal diseases.
Auditory perceptual history is communicated through alpha oscillations
Authors: Ho Hao Tam , Leung Johahn , Burr David C. , Alais David , Morrone Maria Concetta 
Published: February 2019

AbstractSensory expectations from the accumulation of information over time exert strong predictive biases on forthcoming perceptual decisions. These anticipatory mechanisms help to maintain a coherent percept in a noisy environment. Here we present novel behavioural evidence that past sensory experience biases perceptual decisions rhythmically through alpha oscillations. Participants identified the ear of origin of a brief sinusoidal tone masked by dichotic white noise, and response bias oscillated over time at ∼9 Hz. Importantly, the oscillations occurred only for trials preceded by a target to the same ear and lasted for at least two trials. These findings suggest that each stimulus elicits an oscillating memory trace, specific to the ear of origin, which subsequently biases perceptual decisions. This trace is phase-reset by the noise onset of the next trial, and remains within the circuitry of the ear in which it was elicited, modulating the sensory representations in that ear.