bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Potential Sputtering of Lunar Analog Material by Solar Wind Ions
Authors: Szabo Paul S. , Biber Herbert , Jäggi Noah , Brenner Matthias , Weichselbaum David , Niggas Anna , Stadlmayr Reinhard , Primetzhofer Daniel , Nenning Andreas , Mutzke Andreas , Sauer Markus , Fleig Jürgen , Foelske-Schmitz Annette , Mezger Klaus , Lammer Helmut , Galli André , Wurz Peter , Aumayr Friedrich 
Published: March 2020

Abstract
Pyroxenes ((Ca, Mg, Fe, Mn)2Si2O6) belong to the most abundant rock forming minerals that make up the surface of rocky planets and moons. Therefore, sputtering of pyroxenes by solar wind ions has to be considered as a very important process for modifying the surface of planetary bodies. This is increased due to potential sputtering by multiply charged ions; to quantify this effect, sputtering of wollastonite (CaSiO3) by He2+ ions was investigated. Thin films of CaSiO3 deposited on a quartz crystal microbalance were irradiated, allowing precise, in situ, real time sputtering yield measurements. Experimental results were compared with SDTrimSP simulations, which were improved by adapting the used input parameters. On freshly prepared surfaces, He2+ ions show a significant increase in sputtering, as compared to equally fast He+ ions. However, the yield decreases exponentially with fluence, reaching a lower steady state after sputtering of the first few monolayers. Experiments using Ar8+ ions show a similar behavior, which is qualitatively explained by a preferential depletion of surface oxygen due to potential sputtering. A corresponding quantitative model is applied, and the observed potential sputtering behaviors of both He and Ar are reproduced very well. The results of these calculations support the assumption that mainly O atoms are affected by potential sputtering. Based on our findings, we discuss the importance of potential sputtering for the solar wind eroding the lunar surface. Estimated concentration changes and sputtering yields are both in line with previous modeling for other materials, allowing a consistent perspective on the effects of solar wind potential sputtering.
The Energy Sources of Double-peaked Superluminous Supernova PS1-12cil and Luminous Supernova SN 2012aa
Authors: Li Long , Wang Shan-Qin , Liu Liang-Duan , Wang Xiang-Gao , Liang En-Wei , Dai Zi-Gao 
Published: March 2020

Abstract
In this paper, we present the study of the energy reservoir powering the light curves (LCs) of PS1-12cil and SN 2012aa, which are superluminous and luminous supernovae (SNe), respectively. The multiband and bolometric LCs of these two SNe show unusual secondary bumps after the main peaks. The two-peaked LCs cannot be explained by any simple energy-source models (e.g., the 56Ni cascade decay model, the magnetar spindown model, or the ejecta-circumstellar medium interaction model). Therefore, we employ the 56Ni plus ejecta-circumstellar medium (CSM) interaction (CSI) model, the magnetar plus CSI model, and the double CSI model to fit their bolometric LCs, and find that both these two SNe can be explained by the double CSI model and the magnetar plus CSI model. Based on the modeling, we calculate the the time when the shells were expelled by the progenitors: provided that they were powered by double ejecta-shell CSI, the inner and outer shells might be expelled ∼0.2–3.6 and ∼2–25 yr before the explosions of the SNe, respectively; the shells were expelled ∼2–20 yr before the explosions of the SNe if they were powered by magnetars plus CSI.
A Word to the WISE: Confusion is Unavoidable for WISE-selected Infrared Excesses
Authors: Dennihy Erik , Farihi Jay , Fusillo Nicola Pietro Gentile , Debes John H. 
Published: March 2020

Abstract
Stars with excess infrared radiation from circumstellar dust are invaluable for studies of exoplanetary systems, informing our understanding of processes of planet formation and destruction alike. All-sky photometric surveys have made the identification of dusty infrared excess candidates trivial, however, samples that rely on data from Wise Infrared Survey Explorer (WISE) are plagued with source confusion, leading to high false-positive rates. Techniques to limit its contribution to WISE-selected samples have been developed, and their effectiveness is even more important as we near the end-of-life of Spitzer, the only facility capable of confirming the excess. Here, we present a Spitzer follow-up of a sample of 22 WISE-selected infrared excess candidates near the faint-end of the WISE detection limits. Eight of the 22 excesses are deemed the result of source confusion, with the remaining candidates all confirmed by the Spitzer data. We consider the efficacy of ground-based near-infrared imaging and astrometric filtering of samples to limit confusion among the sample. We find that both techniques are worthwhile for vetting candidates, but fail to identify all of the confused excesses, indicating that they cannot be used to confirm WISE-selected infrared excess candidates, but only to rule them out. This result confirms the expectation that WISE-selected infrared excess samples will always suffer from appreciable levels of contamination, and that care should be taken in their interpretation regardless of the filters applied.
An Increasing Radial Velocity of a Narrow Absorption-line System in Quasar SDSS J143530.49+142338.4
Authors: Yao Min , Pan Cai-Juan , LU Wei-Jian , Lin Yin-Ru , Qin Yi-Ping , Liang Wen-Wen , Huang Hong-Yan , Nong Wei-Jing , Lu Mei-Mei , Yao Zhi-Kao 
Published: March 2020

Abstract
We report, for the first time, both the strengthening and radial velocity increases of a narrow absorption-line (NAL) system (C iv
λλ1548, 1551 and N v
λλ1239, 1243) from the two-epoch spectra of quasar SDSS J143530.49+142338.4. First, we speculate that the ionization changes of the outflow clouds are likely the cause of the strengthening in its equivalent width (EW) based on the obvious weakening of the ionization continuum, although other interpretations cannot be ruled out based on the current two-epoch spectra. According to the cloudy simulation, the asynchronized variations between the absorption-line EWs and the ionizing continuum indicate that the absorbers are at relatively high degrees of ionization, which is also consistent with the high ionization state revealed by the absence of Si iv NAL in the same system. Second, this NAL system exhibits a kinematic velocity shift of ∼138

within 445.2 days in the quasar rest frame (corresponding to an average acceleration of ∼0.36

). We evaluate several possible causes for this kinematic shift. However, the current two-epoch spectra do not provide enough constraints to confirm the possible mechanisms, so future monitoring with high resolution will be helpful to achieve this goal.
The Structure of Tidal Disruption Event Host Galaxies on Scales of Tens to Thousands of Parsecs
Authors: French K. Decker , Arcavi Iair , Zabludoff Ann I. , Stone Nicholas , Hiramatsu Daichi , van Velzen Sjoert , McCully Curtis , Jiang Ning 
Published: March 2020

Abstract
We explore the galaxy structure of four tidal disruption event (TDE) host galaxies on 30 pc to kiloparsec scales using Hubble Space Telescope WFC3 multiband imaging. The star formation histories of these hosts are diverse, including one post-starburst galaxy (ASASSN-14li), two hosts with recent weak starbursts (ASASSN-14ae and iPTF15af), and one early-type galaxy (PTF09ge). Compared to early-type galaxies of similar stellar masses, the TDE hosts have higher central surface brightnesses and stellar mass surface densities on 30–100 pc scales. The TDE hosts do not show the large, kiloparsec-scale tidal disruptions seen in some post-starburst galaxies; the hosts have low morphological asymmetries similar to those of early-type galaxies. The lack of strong asymmetries is inconsistent with a recent major (∼1:1 mass) merger, although minor (≲1:3) mergers are possible. Given the time elapsed since the end of the starbursts in the three post-burst TDE hosts and the constraints on the merger mass ratios, it is unlikely that a bound supermassive black hole binary (SMBHB) has had time to coalesce. The TDE hosts have low central (<140 pc) ellipticities compared to early-type galaxies. The low central ellipticities disfavor a strong radial anisotropy as the cause for the enhanced TDE rate, although we cannot rule out eccentric disks at the scale of the black hole gravitational radius of influence (∼1 pc). These observations suggest that the high central stellar densities are a more important driver than SMBHBs or radial anisotropies in increasing the TDE rate in galaxies with recent starbursts.
Accelerated Electrons Observed Down to <7 keV in a NuSTAR Solar Microflare
Authors: Glesener Lindsay , Krucker Säm , Duncan Jessie , Hannah Iain G. , Grefenstette Brian W. , Chen Bin , Smith David M. , White Stephen M. , Hudson Hugh 
Published: March 2020

Abstract
We report the detection of emission from a nonthermal electron distribution in a small solar microflare (GOES class A5.7) observed by the Nuclear Spectroscopic Telescope Array, with supporting observation by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). The flaring plasma is well accounted for by a thick-target model of accelerated electrons collisionally thermalizing within the loop, akin to the “coronal thick-target” behavior occasionally observed in larger flares. This is the first positive detection of nonthermal hard X-rays from the Sun using a direct imager (as opposed to indirectly imaging instruments). The accelerated electron distribution has a spectral index of 6.3 ± 0.7, extends down to at least 6.5 keV, and deposits energy at a rate of ∼2 × 1027 erg s−1, heating the flare loop to at least 10 MK. The existence of dominant nonthermal emission in X-rays down to <5 keV means that RHESSI emission is almost entirely nonthermal, contrary to what is usually assumed in RHESSI spectroscopy. The ratio of nonthermal to thermal energies is similar to that of large flares, in contrast to what has been found in previous studies of small RHESSI flares. We suggest that a coronal thick target may be a common property of many small microflares based on the average electron energy and collisional mean free path. Future observations of this kind will enable understanding of how flare particle acceleration changes across energy scales, and will aid the push toward the observational regime of nanoflares, which are a possible source of significant coronal heating.
The Splash without a Merger
Authors: Amarante João A. S. , Beraldo e Silva Leandro , Debattista Victor P. , Smith Martin C. 
Published: March 2020

Abstract
The Milky Way’s progenitor experienced several merger events that left their imprints on the stellar halo, including the Gaia-Sausage/Enceladus. Recently, it has been proposed that this event perturbed the proto-disk and gave rise to a metal-rich ([Fe/H] > −1), low angular momentum (v

ϕ
< 100 km s−1) stellar population. These stars have dynamical and chemical properties different from the accreted stellar halo, but are continuous with the canonical thick disk. In this Letter, we use a hydrodynamical simulation of an isolated galaxy that develops clumps that produce a bimodal thin+thick disk chemistry to explore whether it forms such a population. We demonstrate that clump scattering forms a metal-rich, low angular momentum population, without the need for a major merger. We show that, in the simulation, these stars have chemistry, kinematics, and density distribution in good agreement with those in the Milky Way.
Enhanced Scheduling Support to Improve Continuity of Care in a Resident Training Clinic
Authors: LaVine Nancy A. , Coletti Daniel J. , Verbsky Jennifer , Block Lauren 
Published: March 2020

ABSTRACT

Background
Clinical continuity is recognized as a driver of satisfaction for patients and physicians. Greater continuity may positively affect trainee decisions to enter primary care. Maintaining clinical continuity remains a challenge in residency clinics.

Objective
We determined whether enhanced scheduling support was associated with improvement in internal medicine resident continuity with patients.

Methods
This study was conducted from June 2017 to December 2018. In the intervention clinic, a single scheduling staff member (ratio of 10 residents to 1 scheduler) was colocated within the clinical space, allowing the scheduler to participate in clinical discussions and direct communication with physicians regarding future appointments. In the comparison clinic, scheduling staff (19:1 ratio) were located at a remote front desk area and relied on patient reports or electronic health record orders to identify appointment needs and arrange follow-up appointments. The main outcome of the intervention was resident continuity, calculated using the continuity for physician formula.

Results
During the study period, mean resident continuity was 23% (range 13%–37%) in the comparison clinic (57 residents) and 54% (range 38%–66%) in the intervention clinic (10 residents). Resident continuity was significantly higher in the intervention clinic compared with the traditional control clinic for every quarter measured (P &lt; .001 for all comparisons).

Conclusions
Enhancing scheduling support through colocation and a lower resident to scheduler ratios was associated with significantly higher rates of resident continuity compared with a traditional front desk model, with results sustained over 18 months.
H-1B Visa Sponsorship and Physician Trainee Retention: A Single Institution Experience
Authors: Abdel-Aziz Yousef , Khan Zubair , Barnett William R. , Altorok Nezam , Assaly Ragheb 
Published: March 2020

ABSTRACT

Background
International medical graduates (IMGs) form a significant portion of the physician workforce in the United States and are vital in filling training slots due to a shortage of American medical graduates. Most often, IMGs require visa sponsorship, which must be solidified before applying for a residency or fellowship.

Objective
We examined the association of H-1B visa sponsorship on retention of physician trainees within the state of Ohio.

Methods
This was a single institutional study that examined all visa-sponsored residency and fellowship graduates who entered fully licensed clinical practice between 2006 and 2015. Practice location was ascertained immediately upon completion of training and at follow-up to determine which visa group (H-1B or J-1) were more likely to initially practice in Ohio after graduation and remain within the state.

Results
Of 103 visa-sponsored residency and fellowship graduates, 42 were H-1B sponsored and 61 were J-1-sponsored. Fifty-two percent (22) of H-1B visa-sponsored trainees and 31% (19) of J-1 visa-sponsored trainees were retained in Ohio after graduation. At follow-up, 40% (17) of H-1B and 26% (16) of J-1 visa holders remained in the state.

Conclusions
H-1B visa–sponsored trainees were more likely than those with J-1 visas to practice in the state of Ohio after graduation. Regardless of visa status, graduates tended not to change their geographical location over time.
On the Mechanisms for Low-Sulfide, High-Platinum Group Element and High-Sulfide, Low-Platinum Group Element Mineralization in the Eastern Gabbro, Coldwell Complex, Canada: Evidence from Textural Associations, S/Se Values, and Platinum Group Element Concentrations of Base Metal Sulfides
Authors: Brzozowski M. J. , Samson I. M. , Gagnon J. E. , Good D. J. , Linnen R. L. 
Published: March 2020

Abstract
The Eastern Gabbro, Coldwell Complex, hosts several geochemically and mineralogically distinct Cu-platinum group element (PGE) deposits, including the high-grade W Horizon (&gt;100 ppm Pd-Pt-Au over 2 m). Several magmatic and/or hydrothermal models have previously been proposed to explain the range of enrichment in PGEs observed in the Marathon deposit, but no work has integrated textural and compositional variations in sulfides to elucidate which of these models is most suitable. Additionally, comparatively little work has been done to characterize the genesis of Cu-PGE mineralization that occurs to the northwest of the Marathon deposit in the Eastern Gabbro. Through integration of base metal sulfide (BMS) mineralogy, texture, and trace element chemistry, a wide range of magmatic and postmagmatic processes have been characterized that contributed to the formation of these deposits. In all zones of mineralization in the Eastern Gabbro, chalcophile elements were remobilized from primary chalcopyrite by hydrothermal fluids and precipitated as secondary chalcopyrite, which occurs as a replacement of pyrrhotite and as intergrowths with hydrous silicates. BMSs in the mineralized zones in the Marathon deposit (Footwall zone, Main zone, and W Horizon) experienced higher R factors than those deposits located northwest of the Marathon deposit (Four Dams, Area 41, and Redstone), with BMSs in the W Horizon having experienced the highest R factors. The silicate melts from which the Footwall zone crystallized likely experienced some degree of sulfide segregation at depth, albeit to a much lesser degree than the northern deposits. Additionally, the melts from which the mineralized zones in the Marathon deposit crystallized were likely contaminated by high-S/Se Archean sedimentary rocks, whereas the northern deposits were likely contaminated by low-S/Se igneous and/or metamorphic rocks. BMSs in a chalcopyrite-rich pod located within the vicinity of the Coldwell Complex experienced both high R factors and high degrees of contamination (cf. W Horizon and Footwall zone, respectively). This study illustrates the complexity of processes that generate and modify mineralization in conduit-type Ni-Cu-PGE systems.
Mesozoic Orogenic Gold Mineralization in the Jiaodong Peninsula, China: A Focused Event at 120 ± 2 Ma During Cooling of Pregold Granite Intrusions
Authors: Zhang Liang , Weinberg Roberto F. , Yang Li-Qiang , Groves David I. , Sai Sheng-Xun , Matchan Erin , Phillips David , Kohn Barry P. , Miggins Daniel P. , Liu Yue , Deng Jun 
Published: March 2020

AbstractJiaodong gold deposits are mainly sited along faulted contacts between Upper Jurassic Linglong granite and Precambrian basement metamorphic rocks or Lower Cretaceous Guojialing granite. Long-standing controversies relate to timing of gold mineralization and granite-gold relationships. In this study, gold-related muscovite consistently provides concordant 40Ar/39Ar plateau ages of 120 ± 2 Ma (2σ) for the Jiaojia, Sizhuang, and Luoshan deposits. Analogous 40Ar/39Ar timing constraints from gold-related muscovite are provided by total gas and high-temperature ages from Fushan, concordant high-temperature ages from Rushan, and fusion-step ages from Xiadian deposits. These new 40Ar/39Ar ages, when combined with previous reliable 40Ar/39Ar and U-Pb age constraints for mineralization, including ages of pre- and postgold dikes, define a widespread gold mineralization event at 120 ± 2 Ma (2σ). Published zircon U-Pb ages for Guojialing and Aishan granite magmatism suggest an ~8-m.y. lag between peak intrusive activity and gold mineralization. This, together with lack of both high-temperature alteration assemblages and alteration and/or metal zonation, indicates that the structurally controlled Jiaodong deposits are orogenic rather than intrusion-related deposits. Despite this, granite intrusions are considered to have provided suitable fluid trap sites. New 40Ar/39Ar analyses of biotite from the Linglong and Guojialing granites show they had cooled to about ~300° ± 50°C by ca. 123 to 124 Ma, providing pressure-temperature conditions similar to those under which most orogenic gold deposits formed close to the ductile-brittle transition. This enabled the effective ingress of fluids at supralithostatic pressures at 120 ± 2 Ma, leading to intensive brecciation, alteration, and deposition of both vein-type and disseminated gold ores. New zircon (U-Th)/He dates together with apatite fission-track data indicate that preservation of the gold province is due to slow postmineralization uplift and exhumation.
“Yes to discuss different models of care between primary care physicians and diabetes-practice nurses, but not to complete implementation yet”: Explorative qualitative study at diabetes clinics in primary health care centres in Muscat, Oman
Authors: Al-Alawi Kamila , Helene Johansson 
Published: March 2020

Background: Globally, many models of care through which the way health services are delivered have been adopted within team-based primary health care. Although these models have aimed to solve some of the health care challenges related to physician’s shortages in clinics and further acceptance of non-physician-led clinics, their application is usually determined by a range of factors, such as preparedness of the health care providers, preparedness of patients and support from higher authorities.Objective: The study was designed to explore health care providers’ perceptions for changes in models of care in diabetes clinics at primary health care in Muscat, Oman.Methods: A total of 27 semi-structured interviews were conducted with health care providers involved in diabetes clinics at five purposively selected primary health care centres in Muscat. The interviewees included the core members of the diabetes management team and other supportive members available at the centres, and were of mixed genders, nationalities and professions. Qualitative thematic analysis was applied.Results: The analysis resulted in one main theme, which captured positive responses towards task-sharing model, but revealed worries and requirements for complete implementation. Nurses’ competences and diabetic patients’ acceptance were among the main concerns. Health care providers revealed that for complete implementation of the model, nurses’ involvement in the team could be improved through updating their knowledge and through the provision of support from higher authorities, while diabetic patients’ acceptance could be improved through understanding of their perceived knowledge towards the model which could promote nurse-led clinics.Conclusion: Task-sharing within the discussed possibilities could provide many positive outcomes and a rewarding future for diabetes clinics at primary health care centres. Omani culture could play a role in its implementation; therefore, if successful implementation is desired, carefully considered steps must be applied by the government and the community.
Narrating the Unspeakable
Authors: Harris Shana 
Published: March 2020

The use of psychedelic substances has been described as an ‘unspeakable primary experience,’ one that is personal and ultimately indescribable. The ineffable quality of such an experience, however, does not prohibit or invalidate attempts to explain it. The struggle to narrate one’s experience is instead an important endeavor. But, how does narration work if the psychedelic experience is truly unspeakable? What kind of narratives are possible? What kinds of narrative work do psychedelics foreclose? This article addresses these questions by analyzing narratives generated about the use of psychedelics for drug treatment. Drawing on 16 months of ethnographic research at drug treatment centers in Baja California, Mexico, this article examines what narration looks like in the context of a psychedelic-based drug treatment modality. It pays particular attention to how people in treatment retell – or struggle to retell – their experiences with psychedelics to make sense of them and then articulate them for the researcher. I argue that psychedelic experiences pose a unique challenge for the anthropological study of these substances, particularly their therapeutic use. I show how these experiences resist narrativization in multiple ways, presenting both ethnographic and epistemological obstacles to the production of anthropological knowledge.