bluuebunny/crossref_metadata_2025_split huggingface dataset:
An expanded ultraluminous X-ray source catalogue
Authors: Bernadich M. C. i , Schwope A. D. , Kovlakas K. , Zezas A. , Traulsen I. 
Published: November 2021

Context. Ultraluminous X-ray sources (LX ≳ ×1039 erg s−1, ULXs) are excellent probes for extreme accretion physics, star formation history in galaxies, and intermediate-mass black holes searches. As the sample size of X-ray data from modern observatories such as XMM-Newton and Chandra increases, producing extensive catalogues of ULXs and studying their collective properties has become both a possibility and a priority.
Aims. Our aim is to build a clean updated ULX catalogue based on one of the most recent XMM-Newton X-ray serendipitous survey data releases, 4XMM-DR9, and the most recent and exhaustive catalogue of nearby galaxies, HECATE. We performed a preliminary population study to test if the properties of the expanded XMM-Newton ULX population are consistent with previous findings.
Methods. We performed positional cross-matches between XMM-Newton sources and HECATE objects to identify host galaxies, and we used distance and luminosity arguments to identify ULX candidates. We flagged interlopers by finding known counterparts in external catalogues and databases such as Gaia DR2, SSDS, Pan-STARRS1, the NASA/IPAC Extragalactic Database, and SIMBAD. Source, galaxy and variability parameters from 4XMM-DR9, HECATE, and 4XMM-DR9s were used to study the spectral, abundance, and variability properties of the ULX sample.
Results. We identify 779 ULX candidates, 94 of which hold LX ≳ 5 × 1040 erg s−1. Spiral galaxies are more likely to host ULXs. For early spiral galaxies the number of ULX candidates per star-forming rate is consistent with previous studies, while a significant ULX population in elliptical and lenticular galaxies also exists. Candidates hosted by late-type galaxies tend to present harder spectra and to undergo more extreme inter-observation variability than those hosted by early-type galaxies. Approximately 30 candidates with LX > 1041 erg s−1 are also identified, constituting the most interesting candidates for intermediate-mass black hole searches.
Conclusions. We have built the largest ULX catalogue to date. Our results on the spectral and abundance properties of ULXs confirm the findings made by previous studies based on XMM-Newton and Chandra data, while our population-scale study on variability properties is unprecedented. Our study, however, provides limited insight into the properties of the brightest ULX candidates due to the small sample size. The expected growth of X-ray catalogues and potential future follow-ups will aid in drawing a clearer picture.
AMICO galaxy clusters in KiDS-DR3: The impact of estimator statistics on the luminosity-mass scaling relation
Authors: Smit Merijn , Dvornik Andrej , Radovich Mario , Kuijken Konrad , Maturi Matteo , Moscardini Lauro , Sereno Mauro 
Published: November 2021

Context.As modern-day precision cosmology aims for statistical uncertainties of the percent level or lower, it becomes increasingly important to reconsider estimator assumptions at each step of the process, along with their consequences on the statistical variability of the scientific results.Aims.We compareL1regression statistics to the weighted mean, the canonicalL2method based on Gaussian assumptions, to infer the weak gravitational shear signal from a catalog of background ellipticity measurements around a sample of clusters, which has been a standard step in the processes of many recent analyses.Methods.We use the shape measurements of background sources around 6925 AMICO clusters detected in the KiDS third data release. We investigate the robustness of our results and the dependence of uncertainties on the signal-to-noise ratios of the background source detections. Using a halo model approach, we derive lensing masses from the estimated excess surface density profiles.Results.The highly significant shear signal allows us to study the scaling relation between ther-band cluster luminosity,L200, and the derived lensing mass,M200. We show the results of the scaling relations derived in 13 bins inL200, with a tightly constrained power-law slope of ∼1.24 ± 0.08. We observe a small, but significant, relative bias of a few percent in the recovered excess surface density profiles between the two regression methods, which translates to a 1σdifference inM200. The efficiency ofL1is at least that of the weighted mean and increases with higher signal-to-noise shape measurements.Concluions.Our results indicate the relevance of optimizing the estimator for inferring the gravitational shear from a distribution of background ellipticities. The interpretation of measured relative biases can be gauged by deeper observations, and the increased computation times remain feasible.
Binary-object spectral-synthesis in 3D (BOSS-3D)
Authors: Hennicker L. , Kee N. D. , Shenar T. , Bodensteiner J. , Abdul-Masih M. , El Mellah I. , Sana H. , Sundqvist J. O. 
Published: November 2021

Context. To quantitatively decode the information stored within an observed spectrum, detailed modelling of the physical state and accurate radiative transfer solution schemes are required. The accuracy of the model is then typically evaluated by comparing the calculated and observed spectra. In the analysis of stellar spectra, the numerical model often needs to account for binary companions and 3D structures in the stellar envelopes. The enigmatic binary (or multiple) system LB-1 constitutes a perfect example of such a complex multi-D problem. Thus far, the LB-1 system has been indirectly investigated by 1D stellar-atmosphere codes and by spectral disentangling techniques, yielding differing conclusions about the nature of the system (e.g., a B-star and black-hole binary with an accretion disc around the black hole or a stripped-star and Be-star binary system have been proposed).
Aims. To improve our understanding of the LB-1 system, we directly modelled the phase-dependent Hα line profiles of this system. To this end, we developed and present a multi-purpose binary-object spectral-synthesis code in 3D (BOSS-3D).
Methods. BOSS-3D calculates synthetic line profiles for a given state of the circumstellar material. The standard pz-geometry commonly used for single stars is extended by defining individual coordinate systems for each involved object and by accounting for the appropriate coordinate transformations. The code is then applied to the LB-1 system, considering two main hypotheses, a binary containing a stripped star and Be star, or a B star and a black hole with a disc.
Results. Comparing these two scenarios, neither model can reproduce the detailed phase-dependent shape of the Hα line profiles. A satisfactory match with the observations, however, is obtained by invoking a disc around the primary object in addition to the Be-star disc or the black-hole accretion disc.
Conclusions. The developed code can be used to model synthetic line profiles for a wide variety of binary systems, ranging from transit spectra of planetary atmospheres, to post-asymptotic giant branch binaries including circumstellar and circumbinary discs and massive-star binaries with stellar winds and disc systems. For the LB-1 system, our modelling provides strong evidence that each object in the system contains a disc-like structure.
Study of the propagation, in situ signatures, and geoeffectiveness of shear-induced coronal mass ejections in different solar winds
Authors: Talpeanu D.-C. , Poedts S. , D’Huys E. , Mierla M. 
Published: November 2021

Aims. Our goal is to propagate multiple eruptions –obtained through numerical simulations performed in a previous study– to 1 AU and to analyse the effects of different background solar winds on their dynamics and structure at Earth. We also aim to improve the understanding of why some consecutive eruptions do not result in the expected geoeffectiveness, and how a secondary coronal mass ejection (CME) can affect the configuration of the preceding one.
Methods. Using the 2.5D magnetohydrodynamics package of the code MPI-AMRVAC, we numerically modelled consecutive CMEs inserted in two different solar winds by imposing shearing motions onto the inner boundary, which in our case represents the low corona. In one of the simulations, the secondary CME was a stealth ejecta resulting from the reconfiguration of the coronal field. The initial magnetic configuration depicts a triple arcade structure shifted southward, and embedded into a bimodal solar wind. We triggered eruptions by imposing shearing motions along the southernmost polarity inversion line, and the computational mesh tracks them via a refinement method that applies to current-carrying structures, and is continuously adapted throughout the simulations. We also compared the signatures of some of our eruptions with those of a multiple CME event that occurred in September 2009 using data from spacecraft around Mercury and Earth. Furthermore, we computed and analysed the Dst index for all the simulations performed.
Results. The observed event fits well at 1 AU with two of our simulations, one with a stealth CME and the other without. This highlights the difficulty of attempting to use in situ observations to distinguish whether or not the second eruption was stealthy, because of the processes the flux ropes undergo during their propagation in the interplanetary space. We simulate the CMEs propagated in two different solar winds, one slow and another faster one. In the first case, plasma blobs arise in the trail of eruptions. The faster solar wind simulations create no plasma blobs in the aftermath of the eruptions, and therefore we interpret them as possible indicators of the initial magnetic configuration, which changes along with the background wind. Interestingly, the Dst computation results in a reduced geoeffectiveness in the case of consecutive CMEs when the flux ropes arrive with a leading positive Bz. When the Bz component is reversed, the geoeffectiveness increases, meaning that the magnetic reconnections with the trailing blobs and eruptions strongly affect the impact of the arriving interplanetary CME.
Escape from the Bermuda cluster: Orphanization by multiple stellar ejections
Authors: Maíz Apellániz J. , Pantaleoni González M. , Barbá R. H. , Weiler M. 
Published: November 2021

Context. Dynamical interactions in young stellar clusters can eject massive stars early in their lives and significantly alter their mass functions. If all of the most massive stars are lost, we are left with an orphan cluster.
Aims. We study the Bermuda cluster (Villafranca O-014 NW), the most significant young stellar group in the North America and Pelican nebulae, and the massive stars that may have been ejected from it to test if it has been orphaned.
Methods. We use Gaia EDR3 parallaxes and proper motions to search for walkaway and runaway stars in the vicinity of the North America and Pelican nebulae. The candidates are analyzed with a combination of spectroscopy and photometry to assess their nature and their trajectories are traced back in time to determine at what time they left the Bermuda cluster.
Results. We detect three ejection events, dubbed the Bajamar, Toronto, and HD 201 795 events, which expelled (a minimum of) five, two, and two systems, respectively, or six, three, and three stars if we count the individual components in spectroscopic and eclipsing binaries. The events took place 1.611 ± 0.011 Ma, 1.496 ± 0.044 Ma, and 1.905 ± 0.037 Ma ago, respectively, but our analysis is marginally consistent with the first two being simultaneous. We detect bow shocks in WISE images associated with four of the ejected systems; their orientation agrees with that of their relative proper motions with respect to the cluster. Combining the three events, the Bermuda cluster has lost over 200 M⊙, including its three most massive stars, so it can be rightfully considered an orphan cluster. One consequence is that the present-day mass function of the cluster has been radically altered from its top-heavy initial value to one compatible with a Kroupa-like function. Another is that the cluster is currently expanding with a dynamical timescale consistent with the cause being the ejection events. A scenario in which the Bermuda cluster was formed in a conveyor-belt fashion over several hundreds of ka or even 1 Ma is consistent with all the observables.
Robust statistical tools for identifying multiple stellar populations in globular clusters in the presence of measurement errors
Authors: Valle G. , Dell’Omodarme M. , Tognelli E. 
Published: November 2021

Context.The finding of multiple stellar populations (MPs), which are defined by patterns in the stellar element abundances, is considered today a distinctive feature of globular clusters. However, while data availability and quality have improved in the past decades, this is not always true for the techniques that are adopted to analyse them, which creates problems of objectivity for the claims and reproducibility.Aims.Using NGC 2808 as test case, we show the use of well-established statistical clustering methods. We focus our analysis on the red giant branch phase, where two data sets are available in the recent literature for low- and high-resolution spectroscopy.Methods.We adopted hierarchical clustering and partition methods. We explicitly addressed the usually neglected problem of measurement errors, for which we relied on techniques that were recently introduced in the statistical literature. The results of the clustering algorithms were subjected to a silhouette width analysis to compare the performance of the split into different numbers of MPs.Results.For both data sets the results of the statistical pipeline are at odds with those reported in the literature. Two MPs are detected for both data sets, while the literature reports five and four MPs from high- and low-resolution spectroscopy, respectively. The silhouette analysis suggests that the population substructure is reliable for high-resolution spectroscopy data, while the actual existence of MP is questionable for the low-resolution spectroscopy data. The discrepancy with literature claims can be explained with the different methods that were adopted to characterise MPs. By means of Monte Carlo simulations and multimodality statistical tests, we show that the often adopted study of the histogram of the differences in some key elements is prone to multiple false-positive findings.Conclusions.The adoption of statistically grounded methods, which adopt all the available information to split the data into subsets and explicitly address the problem of data uncertainty, is of paramount importance to present more robust and reproducible research.
Editorial
Authors: Swart Enno , Gothe Holger , Ihle Peter 
Published: November 2021

Liebe Kolleginnen und Kollegen, Liebe Leserinnen und Leser,vor Ihnen liegt das erste zusammen mit der Hauptschriftleitung von „Das
Gesundheitswesen“ und dem Thieme-Verlag vereinbarte,
regelmäßig ca. halbjährlich erscheinende AGENS-Supplement zu
Methoden und Ergebnissen der Sekundärdatenanalyse. Alle an der Entstehung
dieses Supplements Beteiligten sehen einen hohen Bedarf für ein derartiges
Publikationsmedium, da im deutschsprachigen Raum trotz zunehmender
wissenschaftlicher Nutzung von Sekundärdaten bislang kein spezifisches
Journal existiert, das Sekundärdaten in ihren vielfältigen
Ausprägungen und spezifischen methodischen Herausforderungen explizit zum
Gegenstand hat. Somit stellt das regelmäßige AGENS-Supplement den
Versuch dar, diese Lücke in der deutschen Fachjournal-Landschaft zu
schließen. Die zahlreichen Projekte des Innovationsfonds des Gemeinsamen
Bundesausschusses sind nur ein Beispiel für ein Nutzungsfeld, aus dem heraus
in den nächsten Jahren viele wissenschaftliche Beiträge für
dieses Supplement entstehen dürften. Hinzu kommt der beginnende Aufbau eines
Forschungsdatenzentrums Gesundheit im Zuge der Novellierung des §303a-f SGB
V und der Datentransparenzverordnung (DaTraV; siehe Beitrag in diesem Heft), der
eine zunehmende Nutzung der GKV-Abrechnungsdaten in den nächsten Jahren
erwarten lässt.
Qualitätsvariation in der Schweiz: Analyse der
Mamma-Resektionen bei Brustkrebs anhand des Qualitätsindikators der
Brusterhaltung
Authors: Moser Dominik , von Ahlen Christine , Geissler Alexander 
Published: November 2021

Zusammenfassung
Ziel der Studie Die Studie geht der Frage nach, ob in der Schweiz regionale
Unterschiede bei den Behandlungsergebnissen von elektiven Mamma-Resektionen bei
Brustkrebs bestehen und falls ja, ob eine mögliche Ursache in der
Krankenhausplanung seitens der Kantone zu Grunde liegen könnte.
Methodik Anhand der Inpatient Quality Indicators (CH-IQI) wird die
Ergebnisqualität auf Ebene der Schweizer Kantone analysiert und mit den
kantonalen Anforderungen, um diese Behandlung durchführen zu
können, verglichen.
Ergebnisse Kantonale Unterschiede wurden sowohl bei der
Ergebnisqualität anhand des Qualitätsindikators der
Brusterhaltung als auch bei dem Detaillierungsgrad der Anforderungen an die
Struktur- und Prozessqualität deutlich.
Schlussfolgerung Die Behandlungsqualität ist in der Schweiz kaum
transparent vergleichbar; eine Interpretation der verfügbaren
Qualitätsinformationen ist anspruchsvoll und für Patienten kaum
möglich. Um die aufgezeigten Qualitätsunterschiede zu
reduzieren, sollte die Krankenhausplanung interkantonal erfolgen, wie dies in
der hochspezialisierten Medizin umgesetzt wird.
Prüfung der Stabilität von Implantat-Abutment-Verbindungen im Rotationsschwinger-Test
Authors: Weißweiler Désirée , Niedermeier Wilhelm 
Published: November 2021

ZusammenfassungUntersuchungen hinsichtlich der Stabilität des Implantat-Abutment-Verbundes gibt es bislang lediglich in Anlehnung an die genormte Prüfmethode nach DIN 14801. Es besteht jedoch zusätzlicher Bedarf an Prüfmethoden, die allein schon aus Gründen der Qualitätssicherung in vergleichsweise kurzen Zeitintervallen eine Stabilitätsprüfung dentaler Implantate ermöglichen. Daher sollte ein alternatives Testverfahren auf der Basis des in der Technik etablierten Rotationsschwinger-Tests nach DIN 1311–2 auf seinen praktischen Wert als „Life-Time-Test“ für Implantatsysteme untersucht werden. Durch 2 Versuchsprotokolle mit 30 bzw. 60 Ncm Auslenkmoment wurden unter- und überschwellige Belastungssituationen an 8 verschiedenen Implantat-Abutment-Systemen simuliert und morphologische Veränderungen sowie letztlich die Bruchfestigkeit der jeweils 6 getesteten Prüfkörper untersucht. Dabei änderte sich die Rotationsfreiheit des Abutments signifikant von ursprünglich 1–2° auf bis zu 6°. Das
Lösedrehmoment der Abutmentschraube gab abhängig vom Anzugsdrehmoment signifikant um 10–45% nach. Aufweitungen von bis zu 0,2 mm der Implantathals-Region zeigten sich lediglich bei Frialit-2-Implantaten. Abutmentfrakturen traten in 35% der Fälle auf. Es zeigte sich, dass im Rotationsschwinger-Test innerhalb sehr kurzer Zeit ähnliche Schäden am Implantat-Abutment-Verbund auftreten, wie dies nach jahrelangem Gebrauch von Implantaten auch der Fall ist.
Fat Chance for Hidden Lesions: Pictorial Review of Hoffa's Fat Pad Lesions
Authors: Saxena Suvinay , Patel Drushi D. , Shah Ankur , Doctor Mrugesh 
Published: November 2021

AbstractHoffa's fat pad (HFP) is the most commonly afflicted among all the knee fat pads. Anterior knee pain is common in various pathologies of HFP, as it is richly innervated. A potpourri of the intrinsic and extrinsic pathologies and the tumors and tumor-like conditions affect HFP, and MRI remains the fundamental modality to assess them and provide a specific diagnosis.
Which factors support trust in the recommendation process of pension products? Trust and pension products
Authors: Linhart Philip Maximilian , Stotz Olaf 
Published: November 2021

AbstractDuring the financial crisis of 2008/2009, financial institutions such as banks and insurance companies have lost trust of their customers. In the recommendation process of pension products, trust plays an important role since cash flows from retirement products accrue decades ahead. Using the results from a survey, we find that financial institutions still struggle to deliver trust to their customers when they recommend different categories of retirement products. Other recommending parties such as academic financial experts or close friends, however, are able to establish a high level of trust. We therefore investigate factors of alternative channels to establish trust such as the recommendation process or product features.
Single-frequency erbium-doped fibre laser with random distributed feedback based on disordered structures produced by femtosecond laser radiation
Authors: Skvortsov M.I. , Abdullina S.R. , Wolf A.A. , Dostovalov A.V. , Churin A.E. , Egorova O.N. , Semjonov S.L. , Proskurina K.V. , Babin S.A. 
Published: November 2021

Abstract
Inscription of structures by a femtosecond laser beam allows one to produce disordered structures capable of increasing the Rayleigh backscatter intensity in the fibre at relatively low induced losses, which makes them potential candidates for use as reflectors in fibre lasers. Here we report a narrow-band erbium fibre laser with random distributed feedback produced by femtosecond laser writing in half-open cavity and ring cavity configurations. In the half-open cavity configuration, single-frequency lasing is observed at output powers up to 2.8 W, with a linewidth near 10 kHz. In the ring cavity configuration, single-frequency operation is observed over the entire range of output powers studied. At the highest output power, 7 mW, the linewidth does not exceed 0.7 kHz.
Optical fibres with an inscribed fibre Bragg grating array for sensor systems and random lasers
Authors: Popov S.M. , Butov O.V. , Kolosovskii A.O. , Voloshin V.V. , Vorob’ev I.L. , Isaev V.A. , Ryakhovskii D.V. , Vyatkin M.Yu. , Rybaltovskii A.A. , Fotiadi A.A. , Xia Li , Wang Zhuoying , Lipatov D.S. , Chamorovsky Yu.K. 
Published: November 2021

Abstract
We report the latest results on inscribing extended fibre Bragg grating (FBG) arrays upon fibre drawing, obtained at the Kotelnikov Institute of Radioengineering and Electronics of RAS. The properties of these structures are considered, and examples of their application in sensor systems of microwave dense wavelength multiplexing and as a basis for designing single-frequency fibre lasers are considered. The optical and laser characteristics of FBG arrays, inscribed (using 248-nm UV laser radiation) both in standard single-mode telecommunication fibres of the SMF-28 type and in erbium-doped active fibres, are investigated.