bluuebunny/crossref_metadata_2025_split huggingface dataset:
Technical Constraints on Interstellar Interferometry and Spatially Resolving the Pulsar Magnetosphere
Authors: Popov M. V. , Bartel N. , Andrianov A. S. , Burgin M. S. , Fadeev E. N. , Rudnitskiy A. G. , Smirnova T. V. , Soglasnov V. A. , Zuga V. A. 
Published: August 2023

Abstract
Scintillation of pulsar radio signals caused by the interstellar medium can in principle be used for interstellar interferometry. Changes in the dynamic spectra as a function of pulsar longitude were in the past interpreted as having spatially resolved the pulsar magnetosphere. Guided by this prospect we used very long baseline interferometry observations of PSR B1237+25 with the Arecibo and Green Bank radio telescopes at 324 MHz and analyzed such scintillation at separate longitudes of the pulse profile. We found that the fringe phase characteristics of the visibility function changed quasi-sinusoidally as a function of longitude. Also, the dynamic spectra from each of the telescopes shifted in frequency as a function of longitude. Similar effects were found for PSR B1133+16. However, we show that these effects are not signatures of having resolved the pulsar magnetosphere. Instead, the changes can be related to the effect of low-level digitizing of the pulsar signal. After correcting for these effects the frequency shifts largely disappeared. Residual effects may be partly due to feed polarization impurities. Upper limits for the pulse emission altitudes of PSR B1237+25 would likely be well below the pulsar light cylinder radius. In view of our analysis, we think that observations with the intent of spatially resolving the pulsar magnetosphere need to be critically evaluated in terms of these constraints on interstellar interferometry.
Cosmology with One Galaxy? The ASTRID Model and Robustness
Authors: Echeverri-Rojas Nicolas , Villaescusa-Navarro Francisco , Chawak Chaitanya , Ni Yueying , Hahn ChangHoon , Hernández-Martínez Elena , Teyssier Romain , Anglés-Alcázar Daniel , Dolag Klaus , Castro Tiago 
Published: August 2023

Abstract
Recent work has pointed out the potential existence of a tight relation between the cosmological parameter Ωm, at fixed Ωb, and the properties of individual galaxies in state-of-the-art cosmological hydrodynamic simulations. In this paper, we investigate whether such a relation also holds for galaxies from simulations run with a different code that makes use of a distinct subgrid physics: Astrid. We also find that in this case, neural networks are able to infer the value of Ωm with a ∼10% precision from the properties of individual galaxies, while accounting for astrophysics uncertainties, as modeled in Cosmology and Astrophysics with MachinE Learning (CAMELS). This tight relationship is present at all considered redshifts, z ≤ 3, and the stellar mass, the stellar metallicity, and the maximum circular velocity are among the most important galaxy properties behind the relation. In order to use this method with real galaxies, one needs to quantify its robustness: the accuracy of the model when tested on galaxies generated by codes different from the one used for training. We quantify the robustness of the models by testing them on galaxies from four different codes: IllustrisTNG, SIMBA, Astrid, and Magneticum. We show that the models perform well on a large fraction of the galaxies, but fail dramatically on a small fraction of them. Removing these outliers significantly improves the accuracy of the models across simulation codes.
A Tale of Two Disks: Mapping the Milky Way with the Final Data Release of APOGEE
Authors: Imig Julie , Price Cathryn , Holtzman Jon A. , Stone-Martinez Alexander , Majewski Steven R. , Weinberg David H. , Johnson Jennifer A. , Allende Prieto Carlos , Beaton Rachael L. , Beers Timothy C. , Bizyaev Dmitry , Blanton Michael R. , Brownstein Joel R. , Cunha Katia , Fernández-Trincado José G. , Feuillet Diane K. , Hasselquist Sten , Hayes Christian R. , Jönsson Henrik , Lane Richard R. , Lian Jianhui , Mészáros Szabolcs , Nidever David L. , Robin Annie C. , Shetrone Matthew , Smith Verne , Wilson John C. 
Published: August 2023

Abstract
We present new maps of the Milky Way disk showing the distribution of metallicity ([Fe/H]), α-element abundances ([Mg/Fe]), and stellar age, using a sample of 66,496 red giant stars from the final data release (DR17) of the Apache Point Observatory Galactic Evolution Experiment survey. We measure radial and vertical gradients, quantify the distribution functions for age and metallicity, and explore chemical clock relations across the Milky Way for the low-α disk, high-α disk, and total population independently. The low-α disk exhibits a negative radial metallicity gradient of −0.06 ± 0.001 dex kpc−1, which flattens with distance from the midplane. The high-α disk shows a flat radial gradient in metallicity and age across nearly all locations of the disk. The age and metallicity distribution functions shift from negatively skewed in the inner Galaxy to positively skewed at large radius. Significant bimodality in the [Mg/Fe]–[Fe/H] plane and in the [Mg/Fe]–age relation persist across the entire disk. The age estimates have typical uncertainties of ∼0.15 in log(age) and may be subject to additional systematic errors, which impose limitations on conclusions drawn from this sample. Nevertheless, these results act as critical constraints on galactic evolution models, constraining which physical processes played a dominant role in the formation of the Milky Way disk. We discuss how radial migration predicts many of the observed trends near the solar neighborhood and in the outer disk, but an additional more dramatic evolution history, such as the multi-infall model or a merger event, is needed to explain the chemical and age bimodality elsewhere in the Galaxy.
Survey of X-Rays from Massive Stars Observed at High Spectral Resolution with Chandra
Authors: Pradhan Pragati , Huenemoerder David P. , Ignace Richard , Nichols Joy S. , Pollock A. M. T. 
Published: August 2023

Abstract
Identifying trends between observational data and the range of physical parameters of massive stars is a critical step to the still-elusive full understanding of the source, structure, and evolution of X-ray emission from the stellar winds, requiring a substantial sample size and systematic analysis methods. As of 2022, the Chandra data archive contains 37 high-resolution spectra of O, B, and WR stars, observed with the Chandra/HETGS, and of sufficient quality to fit the continua and emission-line profiles. Using a systematic approach to the data analysis, we explore morphological trends in the line profiles (i.e., O, Ne, Mg, and Si) and find that the centroid offsets of resolved lines versus wavelength can be separated in three empirically defined groups based on the amount of line broadening and centroid offset. Using Fe xvii (15.01, 17.05 Å) and Ne x
α (12.13 Å) lines, which are prevalent among the sample stars, we find a well-correlated linear trend of increasing Full Width Half Maximum with faster wind terminal velocity. The H-like/He-like total line flux ratio for strong lines displays different trends with spectral class depending on ion species. Some of the sources in our sample have peculiar properties (e.g., magnetic and γ Cas-analog stars) and we find that these sources stand out as outliers from more regular trends. Finally, our spectral analysis is presented summarily in terms of X-ray spectral energy distributions in specific luminosity for each source, including tables of line identifications and fluxes.
Cold Solar Flares. I. Microwave Domain
Authors: Lysenko Alexandra L. , White Stephen M. , Zhdanov Dmitry A. , Meshalkina Nataliia S. , Altyntsev Aleksander T. , Motorina Galina G. , Fleishman Gregory D. 
Published: August 2023

Abstract
We identify a set of ∼100 “cold” solar flares and perform a statistical analysis of them in the microwave range. Cold flares are characterized by a weak thermal response relative to nonthermal emission. This work is a follow-up of a previous statistical study of cold flares, which focused on hard X-ray emission to quantify the flare nonthermal component. Here, we focus on the microwave emission. The thermal response is evaluated by the soft X-ray emission measured by the GOES X-ray sensors. We obtain spectral parameters of the flare gyrosynchrotron emission and reveal patterns of their temporal evolution. The main results of the previous statistical study are confirmed: as compared to a “mean” flare, the cold flares have shorter durations, higher spectral peak frequencies, and harder spectral indices above the spectral peak. Nonetheless, there are some cold flares with moderate and low peak frequencies. In the majority of cold flares, we find evidence of the Razin effect in the microwave spectra, indicative of rather dense flaring loops. We discuss the results in the context of the electron acceleration efficiency.
Observational Analysis of Lyα Emission in Equivalent-magnitude Solar Flares
Authors: Greatorex Harry J. , Milligan Ryan O. , Chamberlin Phillip C. 
Published: August 2023

Abstract
The chromospheric Lyα line of neutral hydrogen (1216 Å) is the most intense emission line in the solar spectrum, yet until recently observations of flare-related Lyα emission have been scarce. Here, we examine the relationship between nonthermal electrons accelerated during the impulsive phase of three M3 flares that were co-observed by RHESSI, GOES, and the Solar Dynamics Observatory, and the corresponding response of the chromosphere in Lyα. Despite having identical X-ray magnitudes, these flares showed significantly different Lyα responses. The peak Lyα enhancements above the quiescent background for these flares were 1.5%, 3.3%, and 6.4%. However, the predicted Lyα enhancements from FISM2 were consistently <2.5%. By comparing the properties of the nonthermal electrons derived from spectral analysis of hard X-ray observations, flares with a “harder” spectral index were found to produce a greater Lyα enhancement. The percentage of nonthermal energy radiated by the Lyα line during the impulsive phase was found to range from 2.0% to 7.9%. Comparatively, the radiative losses in He ii (304 Å) were found to range from 0.6% to 1.4% of the nonthermal energy while displaying enhancements above the background of 7.3% to 10.8%. FISM2 was also found to underestimate the level of He ii emission in two of the three flares. These results may have implications for space weather studies and for modeling the response of the terrestrial atmosphere to changes in the solar irradiance, and will guide the interpretation of flare-related Lyα observations that will become available during Solar Cycle 25.
Modeling Star Formation Histories of Post Starburst Galaxies with BAGPIPES
Authors: Crocker Dasha L. , French K. Decker , Tripathi Akshat , Verrico Margaret E. 
Published: August 2023

Abstract
Post-starburst galaxies provide insights into quenching mechanisms. While these galaxies show signs of quiescence, obtaining accurate star formation rates (SFRs) is difficult. This research uses BAGPIPES, a Bayesian spectrum-fitting code, to obtain model spectra of 13 galaxies. From these models, we calculate SFRs over 10 and 100 Myr durations. We compare these SFRs to published Hα and total infrared (TIR) SFRs to examine biases in these measurements. We find that the BAGPIPES-inferred 10, 100 Myr SFRs are comparable with Hα and TIR traced SFRs, respectively, with longer-duration tracers showing systematically higher SFRs.
Exploring Martian Magnetic Fields with a Helicopter
Authors: Mittelholz Anna , Heagy Lindsey , Johnson Catherine L. , Bapst Jonathan , Espley Jared , Fraeman Abigail A. , Langlais Benoit , Lillis Robert , Rapin William 
Published: August 2023

Abstract
The era of helicopter-based surveys on Mars has already begun, creating opportunities for future aerial science investigations with a range of instruments. We argue that magnetometer-based studies can make use of aerial technology to answer some of the key questions regarding early Mars evolution. As such, we discuss mission concepts for a helicopter equipped with a magnetometer on Mars, measurements it would provide, and survey designs that could be implemented. For a range of scenarios, we build magnetization models and test how well structures can be resolved using a range of different inversion approaches. With this work, we provide modeling ground work and recommendations to plan the future of aerial Mars exploration.
MIR Spectra and Analysis of Jovian Trojan Asteroids
Authors: Martin Audrey C. , Emery Joshua P. 
Published: August 2023

Abstract
Jovian Trojan asteroids make up a large group of primitive bodies that populate Jupiter's L4 and L5 Lagrange points. The Trojans’ dynamics and composition carry insight into the formation mechanisms that shaped our solar system. Mid-infrared (MIR; 5–35 μm) spectra of Trojans exhibit puzzling silicate emission features, like spectra of optically thin comet comae, which may be interpreted as “fluffy” regoliths. By understanding the physical properties of the regolith (e.g., particle size and regolith porosity), more accurate compositional interpretations can be made. Here we show 14 Spitzer Space Telescope MIR spectra of Trojans and their compositional makeup. Through parameterization of spectral features and comparison to laboratory and remote-sensing spectra, the results show that the Trojans have highly porous regoliths of fine-particulate crystalline (forsterite, enstatite, and possibly a small amount of fayalite and diopside) and amorphous silicates. These results are consistent with a primordial Kuiper Belt origin.
Microwave Observations of Venus with CLASS
Authors: Dahal Sumit , Brewer Michael K. , Akins Alex B. , Appel John W. , Bennett Charles L. , Bustos Ricardo , Cleary Joseph , Couto Jullianna D. , Datta Rahul , Eimer Joseph , Essinger-Hileman Thomas , Iuliano Jeffrey , Li 李 Yunyang 云炀 , Marriage Tobias A. , Núñez Carolina , Petroff Matthew A. , Reeves Rodrigo , Rostem Karwan , Shi 时 Rui 瑞 , Valle Deniz A. N. , Watts Duncan J. , Weiland Janet L. , Wollack Edward J. , Xu 徐 Zhilei 智磊 
Published: August 2023

Abstract
We report on the disk-averaged absolute brightness temperatures of Venus measured at four microwave frequency bands with the Cosmology Large Angular Scale Surveyor. We measure temperatures of 432.3 ± 2.8, 355.6 ± 1.3, 317.9 ± 1.7, and 294.7 ± 1.9 K for frequency bands centered at 38.8, 93.7, 147.9, and 217.5 GHz, respectively. We do not observe any dependence of the measured brightness temperatures on solar illumination for all four frequency bands. A joint analysis of our measurements with lower-frequency Very Large Array observations suggests relatively warmer (∼7 K higher) mean atmospheric temperatures and lower abundances of microwave continuum absorbers than those inferred from prior radio occultation measurements.
Evaluation of the relationship between insulin resistance and 8-iso prostaglandin levels in obesity children
Authors: Demirhan Ilter , Oner Erkan , Kurutas Ergul Belge 
Published: August 2023

Introduction: The rising rate of childhood obesity and the serious health problems it causes are gaining increasing attention in medical research and health policy.
Aim: This study aimed to evaluate the relationship between insulin resistance and the oxidative stress biomarker 8-iso-prostaglandin F2α levels in obese children.
Materials and methods: Forty-four children in total (21 boys and 23 girls) aged between 6 and 15 years and diagnosed with obesity who attended the Pediatric Endocrinology Unit between December 2020 and June 21 were enrolled in our study. Forty children (20 boys and 20 girls) without systemic diseases were selected as controls. From the percentile curves determined for Turkish children, percentile values of obese children and control group were calculated based on sex and age. In addition, the insulin resistance values (HOMA-IR) in the homeostasis model were calculated. The relationship between the variables was examined with the Pearson and Spearman correlation tests. Children between the 5th and 85th percentile were defined as the control group, and those above the 95th percentile were defined as the obese group. Systolic and diastolic blood pressure, triglyceride, total cholesterol, LDL cholesterol, HDL cholesterol, fasting blood sugar (glucose), insulin, and 8-iso-PGF2α concentrations were measured in all children included in the study.
Results: There were significant differences between the two groups in terms of age, body mass index, and systolic and diastolic blood pressures (p&lt;0.05). Glucose, triglyceride, insulin, 8-iso-PGF2α and HOMA-IR levels were found to be statistically significantly higher in obese children than the levels in the control group (p&lt;0.05). In addition, significant positive correlations were found between insulin levels and glucose, triglyceride and HOMA-IR values in obese patients (p&lt;0.05). In obese children, 8-iso-PGF2α concentrations were found to be statistically significantly higher than those in the control group (p&lt;0.01). ROC analysis had a good diagnostic value for 8-iso-PGF2α where the area under the curve was 1.0. A direct, positive, statistically significant correlation was found between insulin resistance and the 8-iso-PGF2α values (r=0.420, p=0.037).
Conclusions: 8-iso-PGF2α concentrations were found to be higher in obese children than in the control group. It was observed that increased insulin resistance raised 8-iso-PGF2α levels. 8-iso-PGF2α is thought to be particularly important for the diagnosis and treatment of these patients, with 99% sensitivity and specificity.
Effect of Training on the Ability of Nurses to Provide Humanistic Care: Systematic Review and Meta-analysis
Authors: Hu Jian-xin , Chang Rui , Du Jian-qing , He Min 
Published: August 2023

Background:
This article describes a systematic review evaluating the effectiveness of training on the humanistic care abilities of nurses.

Method:

The literature search was conducted in electronic databases to identify studies that evaluated the effect of training on the humanistic care abilities of nurses. Study selection was based on precise eligibility criteria. After the systematic review, a meta-analysis of standardized mean differences (
SMDs
) between posttraining and pretraining humanistic care scale scores was performed to evaluate the effect of training.

Results:

A total of 11 studies were included (624 nurse participants; 97% women; weighted average age = 38.4 years; 95% confidence interval (CI) [31.5, 45.4]). Training schedules varied and ranged from a full-day workshop to brief weekly sessions for up to 2 months. The training framework involved compassion and empathy communication in most of the included studies. Training improved the humanistic care scale scores of the participants (S
MD
= 1.171; 95% CI [0.626, 1.716];
p
< .0001), whereas no significant change was seen in the scores of control subjects (S
MD
= 0.588; 95% CI [−0.536, 1.713];
p
= .305). The effect of training was observable for up to 1 year, although few studies carried out follow-up evaluations.

Conclusion:

Training has the potential to improve the humanistic care abilities of nurses.

[
J Contin Educ Nurs.
2023;54(9):430–436.]
Vitreous Hemorrhage in Pediatric Patients With X-Linked Retinoschisis: Characteristics and Outcomes
Authors: da Cruz Natasha F. S. , Sengillo Jesse D. , Al-Khersan Hasenin , Negron Catherin I. , Felder Marley B. , Patel Nimesh A. , Berrocal Audina M. 
Published: August 2023

Objective:
To report the management and outcomes of vitreous hemorrhage in pediatric patients with X-linked retinoschisis (XLRS).

Materials and Methods:
Retrospective case series of pediatric patients with XLRS with vitreous hemorrhage between January 2000 and January 2022 at the Bascom Palmer Eye Institute.

Results:
Nine patients (12 eyes) met inclusion criteria. The average age at presentation was 5.75 years and mean follow-up time was 6 years. All eyes (58.3%) that underwent fluorescein angiography exhibited peripheral capillary dropout. Six of 12 eyes (50%) were observed without intervention. Four of 12 eyes (33.3%) underwent intravitreal injection of bevacizumab and 2 (16.6%) underwent vitreoretinal surgery. Seven of 12 eyes (58.3%) had documented recurrence of vitreous hemorrhage during follow-up. All retinas were attached and had clear media at final follow-up.

Conclusion:
Fluorescein angiography is a helpful tool to evaluate the vascular phenotype in XLRS. Favorable anatomic outcomes were noted in this cohort, but recurrence of vitreous hemorrhage was common.

[
Ophthalmic Surg Lasers Imaging Retina
2023;54:513–518.]
Lowering the Incidence of Endophthalmitis Following Intravitreal Anti-VEGF Injection: An Analysis of Aseptic Protocol Adjustment
Authors: Uner Ogul E. , Lee Diana , Horesh Remington , Jewart Brian , Seebruck Christopher 
Published: August 2023

Background and Objective:
The impact of anti-sepsis-anesthesia sequence in intravitreal injection (IVI)-associated endophthalmitis is unknown. We compared outcomes of patients who had 10% topical povidone-iodine before or after 2% topical lidocaine gel during IVIs.

Patients and Methods:
A retrospective study of IVIs in nine clinical sites was undertaken. Group 1 had lidocaine gel applied first. This protocol was changed on March 1, 2020, with Group 2 having povidone-iodine applied first. Visual and micro-biological outcomes were compared.

Results:

Among 72 cases (0.07%) from 102,908 IVIs, Group 1 had 59 cases from 65,307 IVI (0.09%) and Group 2 had 13 cases from 37,601 IVI (0.03%;
P
= 0.001). There was no significant difference in the best-corrected visual acuity between groups. Highly virulent bacteria were predominantly isolated in Group 1, but proportions of gram-positive bacterial growth were similar.

Conclusions:
Application of povidone-iodine before lidocaine gel, compared to after, significantly decreased rate of IVI endophthalmitis, with no significant changes in visual and microbiological outcomes.

[
Ophthalmic Surg Lasers Imaging Retina
2023;54:520–525.]
Resuscitation Quality Improvement: Improving Clinicians’ Performance
Authors: Mota Sergio 
Published: August 2023

Background
Although cardiopulmonary resuscitation (CPR) renewal occurs every 2 years, quality of performed CPR at the study site was below American Heart Association (AHA) standards. Resuscitation Quality Improvement (RQI) is a new AHA program with the premise that practicing CPR more frequently using audiovisual feedback can improve performance.

Objective
To identify whether performance of chest compressions during training reassessments improves with RQI.

Methods
This study used a preintervention-postintervention design. Critical care nurses from 2 intensive care units performed a baseline round of chest compressions. These baseline data reflected CPR performance with traditional training. The next week, participants completed RQI training. Two weeks after RQI training, participants performed chest compressions. Five weeks after RQI training, participants performed a third round of chest compressions. The compressions performed 2 and 5 weeks after RQI used audiovisual feedback.

Results
Thirty nurses participated. Before intervention, the mean (SD) for overall compression compliance was 32.68% (26.96%), depth was 67.76% (30.15%), and rate was 39.95% (27.41%). The first postintervention (RQI plus 2 weeks) mean (SD) increased to 75.33% (33.70%) for overall compression compliance, 97.43% (12.04%) for depth, and 80.89% (29.35%) for rate. The second postintervention (RQI plus 5 weeks) mean (SD) decreased slightly to 73.16% (36.36%) for overall compression compliance, 96.57% (13.04%) for depth, and 78.75% (31.83%) for rate.

Conclusion
Frequent CPR using RQI technology, with its immediate audiovisual feedback, helps maintain skills, which may improve patient outcomes.