bluuebunny/crossref_metadata_2025_split huggingface dataset:
UV and X-ray observations of the neutron star LMXB EXO 0748–676 in its quiescent state
Authors: Parikh A S , Degenaar N , Hernández Santisteban J V , Wijnands R , Psaradaki I , Costantini E , Modiano D , Miller J M 
Published: December 2020

ABSTRACT
The accretion behaviour in low-mass X-ray binaries (LMXBs) at low luminosities, especially at &lt;1034 erg s−1, is not well known. This is an important regime to study to obtain a complete understanding of the accretion process in LMXBs, and to determine if systems that host neutron stars with accretion-heated crusts can be used probe the physics of dense matter (which requires their quiescent thermal emission to be uncontaminated by residual accretion). Here, we examine ultraviolet (UV) and X-ray data obtained when EXO 0748–676, a crust-cooling source, was in quiescence. Our Hubble Space Telescope spectroscopy observations do not detect the far-UV continuum emission, but do reveal one strong emission line, C iv. The line is relatively broad (≳3500 km s−1), which could indicate that it results from an outflow such as a pulsar wind. By studying several epochs of X-ray and near-UV data obtained with XMM–Newton, we find no clear indication that the emission in the two wavebands is connected. Moreover, the luminosity ratio of LX/LUV ≳ 100 is much higher than that observed from neutron star LMXBs that exhibit low-level accretion in quiescence. Taken together, this suggests that the UV and X-ray emission of EXO 0748–676 may have different origins, and that thermal emission from crust-cooling of the neutron star, rather than ongoing low-level accretion, may be dominating the observed quiescent X-ray flux evolution of this LMXB.
Evolutionary modelling of subdwarf B stars using mesa with the predictive mixing and convective pre-mixing schemes
Authors: Ostrowski J , Baran A S , Sanjayan S , Sahoo S K 
Published: December 2020

ABSTRACT
The results of the evolutionary modelling of subdwarf B stars are presented. For the first time, we explore the core and near-core mixing in subdwarf B stars using new algorithms available in the mesa code: the predictive mixing scheme and the convective pre-mixing scheme. We show how both methods handle problems related to the determination of the convective boundary and the discrepancy between the core masses obtained from asteroseismology and evolutionary models, and long-standing problems related to the core-helium-burning phase, such as the splitting of the convective core and the occurrence of breathing pulses. We find that the convective pre-mixing scheme is the preferable algorithm. The masses of the convective core in the case of the predictive mixing and the combined convective and semiconvective regions in the case of the convective pre-mixing scheme are higher than in the models with only the Ledoux criterion, but they are still lower than the seismic-derived values. Both algorithms are promising and alternative methods of studying models of subdwarf B stars.
How robustly can we constrain the low-mass end of the z ∼ 6−7 stellar mass function? The limits of lensing models and stellar population assumptions in the Hubble Frontier Fields
Authors: Furtak Lukas J , Atek Hakim , Lehnert Matthew D , Chevallard Jacopo , Charlot Stéphane 
Published: December 2020

ABSTRACT
We present new measurements of the very low mass end of the galaxy stellar mass function (GSMF) at z ∼ 6−7 computed from a rest-frame ultraviolet selected sample of dropout galaxies. These galaxies lie behind the six Hubble Frontier Field clusters and are all gravitationally magnified. Using deep Spitzer/IRAC and Hubble Space Telescope imaging, we derive stellar masses by fitting galaxy spectral energy distributions and explore the impact of different model assumptions and parameter degeneracies on the resulting GSMF. Our sample probes stellar masses down to $M_{\star }\gt 10^{6}\, \text{M}_{\odot}$ and we find the z ∼ 6−7 GSMF to be best parametrized by a modified Schechter function that allows for a turnover at very low masses. Using a Monte Carlo Markov chain analysis of the GSMF, including accurate treatment of lensing uncertainties, we obtain a relatively steep low-mass end slope $\alpha \simeq -1.96_{-0.08}^{+0.09}$ and a turnover at $\log (M_T/\text{M}_{\odot})\simeq 7.10_{-0.56}^{+0.17}$ with a curvature of $\beta \simeq 1.00_{-0.73}^{+0.87}$ for our minimum assumption model with constant star formation history (SFH) and low dust attenuation, AV ≤ 0.2. We find that the z ∼ 6−7 GSMF, in particular its very low mass end, is significantly affected by the assumed functional form of the star formation history and the degeneracy between stellar mass and dust attenuation. For example, the low-mass end slope ranges from $\alpha \simeq -1.82_{-0.07}^{+0.08}$ for an exponentially rising SFH to $\alpha \simeq -2.34_{-0.10}^{+0.11}$ when allowing AV of up to 3.25. Future observations at longer wavelengths and higher angular resolution with the James Webb Space Telescope are required to break these degeneracies and to robustly constrain the stellar mass of galaxies on the extreme low-mass end of the GSMF.
Circular polarization in radio pulsar PSR B1451−68: coherent mode transitions and intrabeam interference
Authors: Dyks J , Weltevrede P , Ilie C 
Published: December 2020

ABSTRACT
The radio emission of pulsar B1451−68 contains two polarization modes of similar strength, which produce two clear orthogonal polarization angle tracks. When viewed on a Poincaré sphere, the emission is composed of two flux patches that rotate meridionally as a function of pulse longitude and pass through the Stokes V poles, which results in transitions between orthogonal polarization modes (OPMs). Moreover, the ratio of power in the patches is inversed once within the profile window. It is shown that the meridional circularization is caused by a coherent OPM transition (COMT) produced by a varying mode ratio at a fixed quarter-wave phase lag. The COMTs may be ubiquitous and difficult to detect in radio pulsar data, because they can leave no trace in polarized fractions and they are described by equation similar to the rotating vector model. The circularization, which coincides with flux minima at lower frequency, requires that profile components are formed by radiation with an oscillation phase that increases with longitude in steps of 90○ per component. The properties can be understood as an interference pattern involving two pairs of linear orthogonal modes (or two non-orthogonal elliptic waves). The frequency-dependent coherent superposition of coplanar oscillations can produce the minima in the pulse profile, and thereby the illusion of components as separate entities. The orthogonally polarized signal that is left after such negative interference explains the enhancement of polarization degree that is commonly observed in the minima between profile components.
Realistic mock observations of the sizes and stellar mass surface densities of massive galaxies in FIRE-2 zoom-in simulations
Authors: Parsotan T , Cochrane R K , Hayward C C , Anglés-Alcázar D , Feldmann R , Faucher-Giguère C A , Wellons S , Hopkins P F 
Published: December 2020

ABSTRACT
The galaxy size–stellar mass and central surface density–stellar mass relationships are fundamental observational constraints on galaxy formation models. However, inferring the physical size of a galaxy from observed stellar emission is non-trivial due to various observational effects, such as the mass-to-light ratio variations that can be caused by non-uniform stellar ages, metallicities, and dust attenuation. Consequently, forward-modelling light-based sizes from simulations is desirable. In this work, we use the skirt  dust radiative transfer code to generate synthetic observations of massive galaxies ($M_{*}\sim 10^{11}\, \rm {M_{\odot }}$ at z = 2, hosted by haloes of mass $M_{\rm {halo}}\sim 10^{12.5}\, \rm {M_{\odot }}$) from high-resolution cosmological zoom-in simulations that form part of the Feedback In Realistic Environments project. The simulations used in this paper include explicit stellar feedback but no active galactic nucleus (AGN) feedback. From each mock observation, we infer the effective radius (Re), as well as the stellar mass surface density within this radius and within $1\, \rm {kpc}$ (Σe and Σ1, respectively). We first investigate how well the intrinsic half-mass radius and stellar mass surface density can be inferred from observables. The majority of predicted sizes and surface densities are within a factor of 2 of the intrinsic values. We then compare our predictions to the observed size–mass relationship and the Σ1−M⋆ and Σe−M⋆ relationships. At z ≳ 2, the simulated massive galaxies are in general agreement with observational scaling relations. At z ≲ 2, they evolve to become too compact but still star forming, in the stellar mass and redshift regime where many of them should be quenched. Our results suggest that some additional source of feedback, such as AGN-driven outflows, is necessary in order to decrease the central densities of the simulated massive galaxies to bring them into agreement with observations at z ≲ 2.
Mass spectrometry-based screening identifies circulating immunoglobulinA–α1-microglobulin complex as potential biomarker in immunoglobulin A nephropathy
Authors: Xu Boyang , Zhu Li , Wang Qingsong , Zhao Yanfeng , Jia Meng , Shi Sufang , Liu Lijun , Lv Jicheng , Lai Wenjia , Ji Jianguo , Zhang Hong 
Published: December 2020

Abstract

Background
Immunoglobulin A nephropathy (IgAN) is characterized by predominant IgA deposition in the glomerular mesangium. Previous studies have proved that renal-deposited IgA in IgAN came from circulating IgA1-containing complexes (CICs).

Methods
To explore the composition of CICs in IgAN, we isolated CICs from IgAN patients and healthy controls and then quantitatively analyzed them by mass spectrometry. Meanwhile, the isolated CICs were used to treat human mesangial cells to monitor mesangial cell injury. Using the protein content and injury effects, the key constituent in CICs was identified. Then the circulating levels of identified key constituent–IgA complex were detected in an independent population by an in-house-developed enzyme-linked immunosorbent assay.

Results
By comparing the proteins of CICs between IgAN patients and controls, we found that 14 proteins showed significantly different levels. Among them, α1-microglobulin content in CICs was associated with not only in vitro mesangial cell proliferation and monocyte chemoattractant protein 1 secretion, but also in vivo estimated glomerular filtration rate (eGFR) levels and tubulointerstitial lesions in IgAN patients. Moreover, we found α1-microglobulin was prone to bind aberrant glycosylated IgA1. Additionally, elevated circulating IgA-α1-microglobulin complex levels were detected in an independent IgAN population and IgA-α1-microglobulin complex levels were correlated with hypertension, eGFR levels and Oxford T- scores in these IgAN patients.

Conclusions
Our results suggest that the IgA-α1-microglobulin complex is an important constituent in CICs and that circulating IgA-α1-microglobulin complex detection might serve as a potential noninvasive biomarker detection method for IgAN.
Going Smokeless: Promotional Features and Reach of US Smokeless Tobacco Direct-Mail Advertising (July 2017–August 2018)
Authors: Czaplicki Lauren , Rahman Basmah , Simpson Randall , Rose Shyanika W , Liu Michael , Perks Siobhan N , Moran Meghan B , Schillo Barbara A 
Published: December 2020

Abstract

Introduction
Although cigarette use in the United States has declined over time, smokeless tobacco (SLT) use has remained steady. Direct-mail advertising and coupon redemption have been linked to increased tobacco use, and efforts to promote SLT through direct-mail advertising may contribute to sustained SLT use. We examined reach of SLT direct-mail advertisements by recipient demographics and promotional features, including coupons.

Methods
Direct-mail data (n = 418) were acquired from Comperemedia (Mintel) and coded for product type (traditional [eg, chewing tobacco], pouched [eg, moist snuff, snus], or both [traditional SLT and any pouched SLT products]); promotions (eg, coupons); flavors; and themes (eg, masculinity). Using Mintel’s volume estimates for number of pieces sent, we calculated the proportion of mail volume sent by recipient demographics (age, income, region) and advertising features across product type.

Results
Between July 2017 and August 2018, tobacco companies sent an estimated 249 million pieces of SLT direct-mail to US households; approximately half (49.6%) featured pouched SLT products. Across product types, over 75% of mail volume was sent to 31- to 60-year-old adults and 30–40% was sent to low-income households. The majority (&gt;70%) of pouched SLT product mail contained coupons and flavor promotions. Outdoor and blue-collar-lifestyle themes were prominent in advertisements for all product types, along with less common adventure- and fun-related appeals.

Conclusions
Coupons, flavors, and a combination of blue-collar and fun/adventure message themes were used to promote traditional and pouched SLT products through direct-mail, particularly to low-income households. Results support limits on direct-mail coupon distribution and continued surveillance of marketing appeals.

Implications
There is a long history of research into tobacco advertising practices, largely focusing on cigarettes. This study highlights specific direct-mail marketing tactics used by the tobacco industry, including coupons to promote SLT products across the United States. Given the limited success in reducing SLT use and the association between direct-mail promotions and tobacco use, these study results provide support for policies to restrict use of coupons in direct-to-consumer tobacco marketing and indicate the need for continued surveillance of direct-mail advertisements as the SLT market continues to evolve.
Industry Payments to Pain Medicine Physicians: An Analysis of the Centers for Medicare and Medicaid Services Open Payments Program
Authors: Goel Vasudha , Patwardhan Amol M , Ibrahim Mohab , Yang Yan , Sivanesan Eellan , Banik Ratan K , Shannon Clarence , Shankar Hariharan 
Published: December 2020

Abstract

Objective
To analyze industry payments to pain medicine physicians in the United States.

Design
Retrospective cohort study using publicly available databases.

Subjects
The study includes U.S. pain medicine physicians (PMPs) with reports in the Open Payments program from 2013 to 2018.

Methods
The Centers for Medicare and Medicaid Services Open Payments program was analyzed for general, investment, and ownership payments to PMPs reported from 2013 to 2018. The nature, type, and geographic variation of payments were analyzed.

Results
The main findings of the study are as follows: 1) Payments made to PMPs constituted a small proportion of the payments made to all physicians in the United States, and the number of transactions and the total dollar amount seem to have decreased from 2016 to 2018. 2) The median number of payments among physicians with reported payments was around 4 (interquartile range: 18), and the majority of them were under $20. 3) The majority of payments were for in-kind items and services (85%) and were made for food and beverages (91%), travel and lodging (5.5%). 4) Some of the ownership and investment interest payments exceeded $500,000. 5) The top five drugs associated with physician payments included medications with opioids. 6) A very small minority of payments were made for entertainment or gifts. 7) A third of PMPs with reports had payments reported under more than one taxonomy.

Conclusions
Overall payments made to PMPs seem to be decreasing since 2016. The majority of the payments are made for the food, beverage, and travel categories. Public and physician awareness of the Open Payments system reports is essential to promote transparency and to minimize adverse effects of financial relationships on patient care.
Who Died in Captivity? Mortality Among Italian Prisoners During World War One
Authors: Fornasin Alessio 
Published: December 2020

Summary
During World War One, almost 600,000 Italian soldiers were captured, and about 50,000 of them died. Most prisoners died of malnutrition and associated illnesses. The aim of this article is to study the differential mortality among Italian prisoners. To achieve this goal, the individual-level data of around 3,500 soldiers born between 1884 and 1899 in North-eastern Italy are used. In this article, the explanatory variables considered are: the military corps which the soldiers belonged to; demographic characteristics, such as age; socio-economic factors, such as occupation and literacy; and anthropometric factors, such as height. The analysis shows that the most experienced prisoners were better able to survive captivity and to overcome deficiencies in diet and illnesses. They were individuals who had the skills and the ability to overcome difficulties and to solve problems both during the conflict and in civil life.
Achieving Success in Prelicensure Registered Nursing Programs: An Explanatory Case Study of African American Men
Authors: Patterson LaDonia D. 
Published: December 2020

Abstract

AIM
The aim of this research was to identify factors that facilitated successful completion of a prelicensure registered nursing program for African American men.

BACKGROUND
Successful completion of prelicensure nursing programs by African American men can increase diversity in the nursing profession. Further investigation is needed to understand the factors that can lead to success in completing prelicensure programs.

METHOD
An explanatory, multiple-case study design was used to explore the personal characteristics, perspectives, and life events of African American men who completed prelicensure nursing programs.

RESULTS
The five factors that influenced success were establishing goals, securing financial resources, maintaining family as a support system, meeting academic expectations, and developing a sense of belonging.

CONCLUSION
Recommendations for how nurse educators can implement strategies to promote success for this population of students are discussed.
Quantification of Ankle Dorsiflexion in Ponseti-managed Unilateral Clubfoot Patients During Early Childhood
Authors: Tougas Caroline M. , Ballester Andrew M. , Morgan Rebecca D. , Ebramzadeh Edward , Sangiorgio Sophia N. , Zionts Lewis E. 
Published: December 2020

Background:
Following the initial correction of a clubfoot using the Ponseti method, diminished passive ankle dorsiflexion may be observed over time, which could represent a possible relapsed deformity. Alternatively, the change may be attributable to patient age or other variables. Our purpose was to quantify passive ankle dorsiflexion in the involved and contralateral unaffected limbs of Ponseti-managed unilateral clubfoot patients, and to determine what patient-related variables influence this finding.

Methods:
In total, 132 unilateral clubfoot patients were studied. Passive ankle dorsiflexion was measured in both limbs at each visit. Data were excluded from visits in which patients showed clear evidence of a relapse. Mean ankle dorsiflexion for clubfeet and contralateral unaffected limbs were reported for annual age intervals and compared using paired t tests. A general linear model was established to assess the effects of age, severity, sex, and side on ankle dorsiflexion.

Results:
Mean ankle dorsiflexion for unaffected limbs declined with age, measuring 53±6 degrees between 0 and 1 year of age and decreasing to 39±7 degrees by 4 to 5 years of age. Similarly, mean ankle dorsiflexion in treated clubfeet declined with age, measuring 44±7 degrees between 0 and 1 year and 29±7 degrees between 4 and 5 years. Overall, the difference between limbs in these patients averaged ~10 degrees for every age interval through 9 years (P<0.001). Ankle dorsiflexion of clubfeet in 95% of patients aged 0 to 2 years was at least 20 degrees, and in 95% of patients aged 3 to 5 years this was at least 15 degrees. Patient age (P<0.001) and severity of deformity (P<0.001) were found to be the only significant factors affecting ankle dorsiflexion in the affected limbs.

Conclusions:
Ankle dorsiflexion in the Ponseti-treated clubfeet was influenced by age of the patient and the initial severity of the affected limb. Furthermore, our data suggest that, in patients who showed no relapse, a minimum of 20 degrees of ankle dorsiflexion in the corrected clubfoot is maintained through age 3 years and a minimum of 15 degrees is maintained through age 5 years.

Level of Evidence:
Level IV—this is a retrospective case series.
Assessing Operative Competency in Cochlear Implantation Across the Residency Training Continuum
Authors: Dowling Eric M. , Carlson Matthew L. 
Published: December 2020

Objective:
To derive normative data based on postgraduate year (PGY) and number of completed otology rotations using a validated tool for cochlear implant surgical competency assessment.

Study Design:
Prospective, blinded validation study.

Setting:
Otolaryngology–Head and Neck Surgery residency training program at a tertiary academic medical center.

Patients:
Fourteen unique otolaryngology trainees, ranging from PGY-1 to PGY-6, were assessed a total of 26 times in a temporal bone laboratory setting using a validated assessment tool for cochlear implantation.

Main Outcome Measures:
Construct validity, internal consistency, and inter-rater reliability.

Results:
Inter-rater reliability was calculated using the Cohen's kappa. Overall agreement between raters was excellent (κ = 0.82). Construct validity was supported by a positive association between higher task-based checklist and global rating scale scores with both trainee PGY level and number of otology rotations completed. Time to complete the exercise was inversely associated with PGY level and number of otology rotations completed.

Conclusion:
Herein, we build upon a previously validated instrument to provide a method to reliably assess surgical competency in a core otologic procedure among residents across the training continuum. This data can be used to provide objective feedback on overall and task-specific competency in cochlear implantation to identify surgical deficiencies early on and to guide supportive course correction.
Classification of the Chorda Tympani: An Endoscopic Study
Authors: Uranaka Tsukasa , Matsumoto Yu , Hoshi Yujiro , Iwasaki Shinichi , Kakigi Akinobu , Yamasoba Tatsuya 
Published: December 2020

Objectives:
To determine the ability of preoperative computed tomography (CT) to predict the variable surgical anatomy of the chorda tympani nerve (CTN) based on endoscopic tympanotomy.

Study Design:
Retrospective case review.

Setting:
Tertiary referral center.

Patients:
We identified 192 ears of 162 patients who underwent transcanal endoscopic ear surgery from August 2013 to June 2018. Patients with middle ear malformations, revision surgeries, myringoplasty, and cholesteatoma involving the CTN were excluded.

Intervention(s):
An intraoperative endoscopic image depicting the chorda tympani was selected for each patient and classified into one of five types. Preoperative CT images were analyzed to match the pictorial classification.

Main Outcome Measure(s):
The visible tympanic segment of the chorda tympani was classified into the following five types: external auditory canal (EAC), detached, attached long, attached short, and ultrashort.

Results:
A total of 128 ears from 101 patients ranging in age from 2 to 81 years were enrolled. The EAC, detached, attached long, attached short, and ultrashort types of CTN were found in 7 (5.5%), 6 (4.7%), 84 (65.6%), 18 (14.0%), and 13 (10.2%) patients, respectively. The presence of the EAC type could be predicted by preoperative CT while the other four types could be predicted by binning into two groups, with a sensitivity of 0.61 and specificity of 0.72.

Conclusion:
The variable anatomy of the chorda tympani nerve can be classified into five major groups based on endoscopic tympanotomy.