bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Terrestrial-mass Rogue Planet Candidate Detected in the Shortest-timescale Microlensing Event
Authors: Mróz Przemek , Poleski Radosław , Gould Andrew , Udalski Andrzej , Sumi Takahiro ,   and, Szymański Michał K. , Soszyński Igor , Pietrukowicz Paweł , Kozłowski Szymon , Skowron Jan , Ulaczyk Krzysztof ,   (OGLE Collaboration), Albrow Michael D. , Chung Sun-Ju , Han Cheongho , Hwang Kyu-Ha , Jung Youn Kil , Kim Hyoun-Woo , Ryu Yoon-Hyun , Shin In-Gu , Shvartzvald Yossi , Yee Jennifer C. , Zang Weicheng , Cha Sang-Mok , Kim Dong-Jin , Kim Seung-Lee , Lee Chung-Uk , Lee Dong-Joo , Lee Yongseok , Park Byeong-Gon , Pogge Richard W. ,   (KMT Collaboration)
Published: October 2020

Abstract
Some low-mass planets are expected to be ejected from their parent planetary systems during early stages of planetary system formation. According to planet formation theories, such as the core accretion theory, typical masses of ejected planets should be between 0.3 and 1.0 M
⊕. Although in practice such objects do not emit any light, they may be detected using gravitational microlensing via their light-bending gravity. Microlensing events due to terrestrial-mass rogue planets are expected to have extremely small angular Einstein radii (≲1 μas) and extremely short timescales (≲0.1 day). Here, we present the discovery of the shortest-timescale microlensing event, OGLE-2016-BLG-1928, identified to date (

). Thanks to the detection of finite-source effects in the light curve of the event, we were able to measure the angular Einstein radius of the lens

μas, making the event the most extreme short-timescale microlens discovered to date. Depending on its unknown distance, the lens may be a Mars- to Earth-mass object, with the former possibility favored by the Gaia proper motion measurement of the source. The planet may be orbiting a star but we rule out the presence of stellar companions up to the projected distance of ∼8.0 au from the planet. Our discovery demonstrates that terrestrial-mass free-floating planets can be detected and characterized using microlensing.
HAWC and Fermi-LAT Detection of Extended Emission from the Unidentified Source 2HWC J2006+341
Authors: Albert A. , Alfaro R. , Alvarez C. , Camacho J. R. Angeles , Araya M. , Arteaga-Velázquez J. C. , Arunbabu K. P. , Rojas D. Avila , Solares H. A. Ayala , Baghmanyan V. , Belmont-Moreno E. , Brisbois C. , Caballero-Mora K. S. , Carramiñana A. , Casanova S. , Cotti U. , la Fuente E. De , de León C. , Hernandez R. Diaz , Dingus B. L. , DuVernois M. A. , Durocher M. , Díaz-Vélez J. C. , Espinoza C. , Fleischhack H. , Fraija N. , Galván-Gámez A. , Garcia D. , García-González J. A. , Garfias F. , González M. M. , Goodman J. A. , Harding J. P. , Hona B. , Huang D. , Hueyotl-Zahuantitla F. , Hüntemeyer P. , Iriarte A. , Jardin-Blicq A. , Joshi V. , Vargas H. León , Linnemann J. T. , Longinotti A. L. , López-Coto R. , Luis-Raya G. , Lundeen J. , Malone K. , Martinez O. , Martínez-Castro J. , Matthews J. A. , Miranda-Romagnoli P. , Moreno E. , Mostafá M. , Nellen L. , Nisa M. U. , Noriega-Papaqui R. , Omodei N. , Peisker A. , Pérez-Pérez E. G. , Rho C. D. , Rosa-González D. , Greus F. Salesa , Sandoval A. , Schneider M. , Springer R. W. , Tollefson K. , Torres I. , Torres-Escobedo R. , Ureña-Mena F. , Villaseñor L. , Weisgarber T. , Willox E. , Zepeda A. , Zhou H. ,   (HAWC Collaboration)
Published: October 2020

Abstract
The discovery of the TeV point source 2HWC J2006+341 was reported in the second HAWC gamma-ray catalog. We present a follow-up study of this source here. The TeV emission is best described by an extended source with a soft spectrum. At GeV energies, an extended source is significantly detected in Fermi-LAT data. The matching locations, sizes, and spectra suggest that both gamma-ray detections correspond to the same source. Different scenarios for the origin of the emission are considered and we rule out an association to the pulsar PSR J2004+3429 due to extreme energetics required, if located at a distance of 10.8 kpc.
A Magnetized, Moon-forming Giant Impact
Authors: Mullen P. D. , Gammie C. F. 
Published: October 2020

Abstract
The Moon is believed to have formed in the aftermath of a giant impact between a planetary-mass body and the proto-Earth. In a typical giant impact scenario, a disk of vapor, liquid, and solid debris forms around the proto-Earth and—after possibly decades of evolution—condenses to form the Moon. Using state-of-the-art numerical simulations, we investigate the dynamical effects of magnetic fields on the Moon-forming giant impact. We show that turbulence generated by the collision itself, shear in the boundary layer between the post-impact debris field and the proto-Earth, and turbulence in the vapor component of the disk amplify the field to dynamically significant strengths. Magnetically driven turbulence promotes angular momentum transport in the protolunar disk. Debris material is accreted onto the proto-Earth, making Moon formation less efficient, while the disk is forced to spread to larger radii, cooling at its outer edge. Magnetic fields speed the evolution of the vapor component of the protolunar disk and hasten the formation of the Moon.
Discovery of a Large Population of Nitrogen-enhanced Stars in the Magellanic Clouds
Authors: Fernández-Trincado José G. , Beers Timothy C. , Minniti Dante , Carigi Leticia , Barbuy Beatriz , Placco Vinicius M. , Bidin Christian Moni , Villanova Sandro , Roman-Lopes Alexandre , Nitschelm Christian 
Published: October 2020

Abstract
We report the APOGEE-2S+ discovery of a unique collection of nitrogen-enhanced mildly metal-poor giant stars, peaking at [Fe/H] ∼ −0.89 with no carbon enrichment, toward the Small and Large Magellanic Clouds (SMC and LMC), with abundances of light- (C, N), odd-Z (Al, K), and α-elements (O, Mg, Si) that are typically found in Galactic globular clusters (GCs). Here we present 44 stars in the SMC and LMC that exhibit significantly enhanced [N/Fe] abundance ratios, well above ([N/Fe] ≳ +0.6) typical Galactic levels at similar metallicity, and a star that is very nitrogen-enhanced ([N/Fe] > +2.45). Our sample consists of luminous evolved stars on the asymptotic giant branch (AGB), eight of which are classified as bona fide semi-regular (SR) variables, as well as low-luminosity stars similar to those of stars on the tip of the red giant branch of stellar clusters in the SMC and LMC. It seems likely that whatever nucleosynthetic process is responsible for these anomalous SMC and LMC stars it is similar to that which caused the common stellar populations in GCs. We interpret these distinctive C–N patterns as observational evidence of the result of tidally shredded GCs in the SMC and LMC. These findings might explain some previous conflicting results over bulge N-rich stars, and broadly help to understand GC formation and evolution. Furthermore, the discovery of such a large population of N-rich AGB stars in the SMC and LMC suggests that multiple stellar populations might not only be exotic events from the past, but can also form at lower redshift.
Effects of Spin on Constraining the Seeds and Growth of ≳109M⊙ Supermassive Black Holes in z > 6.5 Quasars
Authors: Zhang Xiaoxia , Lu Youjun , Fang Taotao 
Published: October 2020

Abstract
The existence of ≳109
M
⊙ supermassive black holes (SMBHs) at redshift z > 6 raises the problem of how such SMBHs can grow up within the cosmic time (<1 Gyr) from small seed BHs. In this Letter, we use the observations of 14 quasars at z > 6.5 with mass estimates to constrain their seeds and early growth, by self-consistently considering the spin evolution and the possibility of super-Eddington accretion. We find that spin plays an important role in the growth of early SMBHs, and the constraints on seed mass and super-Eddington accretion fraction strongly depend on the assumed accretion history. If the accretion is coherent with single (or a small number of) episode(s), leading to high spins for the majority of accretion time, then the SMBH growth is relatively slow; and if the accretion is chaotic with many episodes and in each episode the total accreted mass is much less than the SMBH mass, leading to moderate/low spins, then the growth is relatively fast. The constraints on the seed mass and super-Eddington accretion fraction are degenerate. A significant fraction (≳0.1%–1% in linear scale but ∼3–4 dex in logarithmic scale for 103–104
M
⊙ seeds) of super-Eddington accretion is required if the seed mass is not ≫105
M
⊙, and the requirements of high seed mass and/or super-Eddington accretion fraction are moderately relaxed if the accretion is chaotic.
Tearing Modes in Partially Ionized Astrophysical Plasma
Authors: Pucci Fulvia , Singh K. Alkendra P. , Tenerani Anna , Velli Marco 
Published: October 2020

Abstract
In many astrophysical environments the plasma is only partially ionized, and therefore the interaction of charged and neutral particles may alter both the triggering of reconnection and its subsequent dynamical evolution. We derive the tearing mode maximum growth rate for partially ionized plasmas in the cases of weak and strong coupling between the plasma and the neutrals. In addition, critical scalings for current sheet aspect ratios are presented in terms of Lundquist number and ion–neutral collision frequencies for which the tearing mode becomes fast, or ideal. In the decoupled regime the standard tearing mode is recovered with a small correction that depends on the ion–neutral collision frequency; in the intermediate regime collisions with neutrals are shown to stabilize current sheets, resulting in larger critical aspect ratios for ideal tearing to occur. In the coupled regime, the growth rate depends on the density ratio between ions and neutrals through the collision frequency between these two species.
Observable Signatures of the Ejection Speed of Interstellar Objects from Their Birth Systems
Authors: Siraj Amir , Loeb Abraham 
Published: October 2020

Abstract
‘Oumuamua and Borisov were the first two interstellar objects confirmed in the solar system. The upcoming commencement of the Vera C. Rubin Observatory’s Legacy Survey of Space of Time (LSST) will enhance greatly the discovery rate of interstellar objects. This raises the question, what can be learned from large-number statistics of interstellar objects? Here, we show that discovery statistics provided by LSST will allow low- and high-ejection-speed populations to be distinguished using the velocity dispersion and angular anisotropy of interstellar objects. These findings can be combined with physical characterizations to yield a better understanding of planetary system origin and nature.
Entre faillibilisme et convivialisme : le rapport aux vérités professionnelles en formation des enseignant.e.s
Authors: Capitanescu Benetti Andreea , Maulini Olivier 
Published: October 2020

La vérité est-elle une valeur chère aux professionnels de l’enseignement : non seulement dans leur travail avec les élèves, mais aussi entre eux, à propos de leurs propres savoirs ? Une démarche de recherche ancrée dans des pratiques de formation initiale et continue pour l’enseignement primaire montre une tension entre deux rapports au monde : faillibiliste et convivialiste. Le premier est valorisé par les formateurs, qui recherchent les conflits de normes pouvant mener à des connaissances attestées : des prétentions à la vérité dûment discutées. Le second domine chez les praticiens, d’abord soucieux d’intégration et de différenciation sans rapports de force : les controverses potentielles peuvent s’en trouver neutralisées. L’étude de deux situations emblématiques – l’une en formation initiale, l’autre en formation continue – montre chaque fois un même schème à l’œuvre : le besoin de s’accorder et/ou de cohabiter l’emporte sur la quête d’antagonismes susceptibles de trancher entre le vrai et le faux, le vraisemblable et le contestable, l’affirmation vérifiable et la préférence élective. L’opposition de sens commun entre théorie et pratique pourrait ainsi occulter la véritable tension entre deux rapports au savoir plus implicites et ainsi complexes à confronter. Il semble dès lors important de prolonger l’enquête en cherchant quelles dispositions peuvent sous-tendre le schème de neutralisation, entre souci de s’affilier et crainte d’en être altéré.
Integrating Environmental Sustainability Content Into an RN-to-BSN Program: A Pilot Study
Authors: Linton Mary E. , Wilson Kristi Jo , Dabney Beverly W. , Johns Edgar F. 
Published: October 2020

Background:
The link between environmental sustainability, climate change, and health outcomes makes environmental sustainability an important topic for educators to include in nursing curricula.

Method:
Students completed a sustainability in nursing learning module, over a 4-week period, during which students created blog posts based on the learning materials and clinical practice observations. The Sustainability Attitudes in Nursing Survey questionnaire was incorporated to measure changes in student attitudes regarding sustainability.

Results:

Descriptive statistics indicated that students had higher average scores on the posttest for all variables except one measurement. Paired
t
-test results revealed statistically significant differences in nine sustainability attitude items in the pretest and posttest scores. These findings suggest that the intervention likely contributed to improved attitudes about sustainability in the workplace.

Conclusion:

Results of this study are promising because the brief intervention had a significant effect on practicing nurses' attitudes about sustainability in their work environments.

[
J Nurs Educ.
2020;59(11):637–641.]
Escape Room Relay Race: “Go for the Gold” in Formative Assessment
Authors: Darby Wendy , Bergeron Peggy , Brown Neysa , DeFoor Melissa , Jones Brittney 
Published: October 2020

Background:
Immersive learning activities, such as escape room educational gaming in nursing simulation laboratories, have proven to be effective teaching strategies that promote communication and teamwork. These activities also provide educators with opportunities to assess clinical skills competencies, as well as providing them with a means for evaluating the transfer of didactic knowledge to clinical practice.

Method:
An obstetrical skills relay race with an escape room element was created as a formative evaluation method to determine if nursing students were able to demonstrate competency related to the identified learning needs.

Results:
The competitive aspects of this learning activity were perceived as exciting and motivating by the educators and students.

Conclusion:

An escape room–themed relay race incorporated into an obstetric skills laboratory is considered an innovative and formative evaluation method, as well as an engaging and motivating learning activity for nursing students.

[
J Nurs. Educ.
2020;59(11):646–650.]
Learning Analytics for Blended Learning: A Systematic Review of Theory, Methodology, and Ethical Considerations
Authors: Bergdahl Nina , Nouri Jalal , Karunaratne Thashmee , Afzaal Muhammad , Saqr Mohammed 
Published: October 2020

<p>Learning Analytics (LA) approaches in Blended Learning (BL) research is becoming an established field. In the light of previous critiqued toward LA for not being grounded in theory, the General Data Protection and a renewed focus on individuals’ integrity, this review aims to explore the use of theories, the methodological and analytic approaches in educational settings, along with surveying ethical and legal considerations. The review also maps and explores the outcomes and discusses the pitfalls and potentials currently seen in the field. Journal articles and conference papers were identified through systematic search across relevant databases. 70 papers met the inclusion criteria: they applied LA within a BL setting, were peer-reviewed, full-papers, and if they were in English. The results reveal that the use of theoretical and methodological approaches was disperse, we identified approaches of BL not included in categories of BL in existing BL literature and suggest these may be referred to as hybrid blended learning, that ethical considerations and legal requirements have often been overlooked. We highlight critical issues that contribute to raise awareness and inform alignment for future research to ameliorate diffuse applications within the field of LA.</p>
Judeus e motivos de origem hebraica no Livro das Cantigas de Dom Pedro, Conde de Barcelos
Authors: Miranda José Carlos Ribeiro 
Published: October 2020

Sendo embora um movimento poético europeu, cristão e românico, que se desenrolou desde finais do século XII até meados do século XIV, a poesia galego-portuguesa deu testemunho do convívio com as comunidades e a cultura judaicas peninsulares. Ao longo do século XIV, dois poetas judeus revelam-se mesmo plenamente inseridos nos dos padrões formais trovadorescos, sendo poemas de sua autoria recolhidos no cancioneiro organizado por Dom Pedro, Conde de Barcelos. Porém, é numa cantiga de Afonso XI de Castela que melhor se reflecte esse convívio cultural, já que o rei castelhano se utiliza imagens muito próximas da poesia de Yeudah Halevi, tendo como pano de fundo a glosa erótica do Cântico dos Cânticos.
Norlevo e obiezione di coscienza
Authors: Di Pietro M.L. , Casini M. , Fiori A. , Minacori R. , Romano L. , Bompiani A. 
Published: October 2020

L’autorizzazione della commercializzazione, in Italia, del Norlevo - prodotto a base di levonorgestrel - come contraccettivo d’emergenza (Decreto AIC/UAC n. 510/2000 del 26.09.2000) ha sollevato un intenso dibattito sul comportamento del medico che non vuole prescrivere per ragioni deontologiche ed etiche, sostanze che possano ostacolare il proseguimento dello sviluppo del concepito. Ci si chiede, inoltre, se questa decisione possa rientrare nella fattispecie prevista dall’art. 9 della Legge 194/78 in materia di obiezione di coscienza.
Per dare una risposta a questo interrogativo, è stato necessario studiare, innanzitutto, il meccanismo di azione del levonorgestrel: solo qualora si fosse riscontrata la possibilità di un effetto abortivo, sarebbe stato possibile appellarsi alla suddetta legge. Poiché si è giunti alla conclusione che, accanto all’unico effetto contraccettivo (inibizione/ritardo dell’ovulazione) dimostrato, sono presenti anche e soprattutto effetti in fase post-fertilizzazione, è stata presa in esame la riflessione giuridica in materia.
Alla luce dell’ordinamento italiano e delle decisioni della Corte Costituzionale, il rifiuto di prescrivere/somministrare il Norlevo rientra nelle previsioni dell’art. 9 della Legge 194/78, ma anche qualora questo non venisse riconosciuto, si rende sempre configurabile - a fronte del bene “vita umana” - anche una sorta di “clausola di coscienza” in base alla quale il medico ha diritto ad agire secondo i propri convincimenti interiori.
Popolazione e fame nel mondo: agricoltura, alimenti, sviluppo
Authors: Postiglione Luigi 
Published: October 2020

L’agricoltura fornisce gli alimenti per la nutrizione, costituisce uno dei principali mezzi per ristabilire l’equilibrio dell’agroecosistema ed è motore primo dello sviluppo. Però oggi i 4/5 della popolazione mondiale, in continua crescita, soffrono per carenza di cibo; e ciò, per buona parte, a causa della cattiva distribuzione delle produzioni agricole, delle quali, purtroppo, nei Paesi sviluppati se ne distrugge una parte per ragioni di mercato.
Nel secolo XX, invero, la disponibilità di alimenti ha subito consistenti aumenti, sia per un forte aumento della produzione areica (aumentata in media di 4-5 volte) sia per l’aumento della superficie coltivata (messa a coltura di terreni prima non coltivati, bonifica, irrigazione), tanto che nei Paesi industrializzati oggi si dà molto più spazio alla qualità dei prodotti. Il detto aumento è dovuto principalmente alle moderne tecnologie e all’impiego di consistenti mezzi tecnici (concimi, fitofarmaci), questi ultimi spesso causa d’inquinamento e di notevole consumo di energia fossile.
Tuttavia vi è la possibilità di aumentare ancora l produzione, nel rispetto dell’ambiente, con l’agricoltura ecocompatibile che prevede l’impiego corretto dei mezzi tecnici, il ritorno ad antiche pratiche agricole con nuovo significato. Vi è altresì la possibilità di utilizzare l’agricoltura per l’equilibrio dell’agroecosistema (difesa del suolo, riduzione dell’anidride carbonica nell’atmosfera).
Questi obiettivi, già molto impegnativi nei Paesi industrializzati, vanno perseguiti con attenzione nei Paesi in via di sviluppo, coinvolgendo maestranze e dirigenti locali e suggerendo modelli di sviluppo che tengano conto delle caratteristiche ambientali di ciascuna zona (condizioni socio-culturali e condizioni pedoclimatiche).
L’autore, dopo di aver esaminato i problemi tecnico-scientifici connessi con ciascun argomento trattato, chiude con una nota di ottimismo, desunta dalla sua lunga attività di agronomo trattato, chiude con una nota di ottimismo, desunta dalla sua lunga attività di agronomi e dalla conoscenza diretta delle potenzialità produttive di diverse regioni del mondo, nonché dagli studi di altri autori. Afferma, cioè, che l’agricoltura è in grado di fornire gli alimenti per tutti gli abitanti del Pianeta, purché si vincano gli egoismi di alcune nazioni, e nelle previsioni lo sarà anche quando nel 2030 gli abitanti saranno 8,27 miliardi.
Le sperimentazioni internazionali Il dibattito sugli studi placebo-controllati
Authors: Torlone Gaetano 
Published: October 2020

Il lavoro proposto prende spunto da un articolo apparso sul New England Journal of Medicine del 1997 a firma di P. Lurie e S.M. Wolfe. In questo articolo gli autori descrivevano come non etici alcuni studi sull’efficacia di dosi ridotte di AZT nella trasmissione materno-fetale dell’HIV. Tali studi erano sponsorizzati da organizzazioni occidentali e realizzati in paesi dell’Africa subsahariana e in Asia. Il nodo etico più importante messo in luce era l’utilizzo di un braccio placebo-controllato anche se era già nota l’efficacia del trattamento a base di zidovudina per la riduzione della trasmissione perinatale dell’infezione grazie ad uno studio (ACTG 076) effettuato negli USA e in Francia e che aveva indicato la zidovudina come terapia standard.
Nella prima parte del presente lavoro analizziamo la letteratura scientifica internazionale nei quinquenni precedente e successivo alla pubblicazione dell’articolo di Lurie e Wolfe. Da tale analisi appare un incremento statisticamente significativo delle pubblicazioni sull’etica della ricerca clinica nei paesi in via di sviluppo negli ultimi anni.
Nella seconda parte del lavoro invece si cerca di analizzare il tema specifico della giustificazione etica dell’uso del braccio placebo-controllato in sperimentazioni effettuate nei paesi in via di sviluppo pur esistendo una terapia standard. Si approfondiscono pertanto le posizioni favorevoli e quelle contrarie, soprattutto facendo riferimento agli strumenti interpretativi elaborati da A.J. London.
Le conclusioni raggiunte forniscono indicazioni generali sulla non eticità, dal punto di vista etico e logico, dell’utilizzo del braccio placebo-controllato nelle sperimentazioni nei paesi in via di sviluppo quando si conosca una terapia standard per la patologia in studio. Tuttavia rimane aperta la discussione per quel che riguarda la “generalizzabilità” dei risultati di un trial a popolazioni di differente identità storica e culturale.