bluuebunny/crossref_metadata_2025_split huggingface dataset:
The HH 24 Complex: Jets, Multiple Star Formation, and Orphaned Protostars
Authors: Reipurth Bo , Bally J. , Yen Hsi-Wei , Arce H. G. , Rodríguez L.-F. , Raga A. C. , Geballe T. R. , Rao R. , Comerón F. , Mikkola S. , Aspin C. A. , Walawender J. 
Published: April 2023

Abstract
The HH 24 complex harbors five collimated jets emanating from a small protostellar multiple system. We have carried out a multiwavelength study of the jets, their driving sources, and the cloud core hosting the embedded stellar system, based on data from the Hubble Space Telescope, Gemini, Subaru, Apache Point Observatory 3.5 m, Karl G. Jansky Very Large Array, and Atacama Large Millimeter/submillimeter Array (ALMA) telescopes. The data show that the multiple system, SSV 63, contains at least 7 sources, ranging in mass from the hydrogen-burning limit to proto-Herbig Ae stars. The stars are in an unstable nonhierarchical configuration, and one member, a borderline brown dwarf, is moving away from the protostellar system with 25 km s−1, after being ejected ∼5800 yr ago as an orphaned protostar. Five of the embedded sources are surrounded by small, possibly truncated, disks resolved at 1.3 mm with ALMA. Proper motions and radial velocities imply jet speeds of 200–300 km s−1. The two main HH 24 jets, E and C, form a bipolar jet system that traces the innermost portions of parsec-scale chains of Herbig–Haro and H2 shocks with a total extent of at least 3 pc. H2CO and C18O observations show that the core has been churned and continuously fed by an infalling streamer. 13CO and 12CO trace compact, low-velocity, cavity walls carved by the jets and an ultracompact molecular outflow from the most embedded object. Chaotic N-body dynamics likely will eject several more of these objects. The ejection of stars from their feeding zones sets their masses. Dynamical decay of nonhierarchical systems can thus be a major contributor to establishing the initial mass function.
Modeling Two First Hydrostatic Core Candidates Barnard 1b-N and 1b-S
Authors: Duan 段 Hao-Yuan 皓元 , Lai 賴 Shih-Ping 詩萍 , Hirano 平野 Naomi 尚美 , Thieme 陸 Travis J. 哲軒 
Published: April 2023

Abstract
A first hydrostatic core (FHC) is proposed to form after the initial collapse of a prestellar core, as a seed of a Class 0 protostar. FHCs are difficult to observe because they are small, compact, embedded, and short lived. In this work, we explored the physical properties of two well-known FHC candidates, B1-bN and B1-bS, by comparing interferometric data from Submillimeter Array (SMA) 1.1 and 1.3 mm and Atacama Large Millimeter/submillimeter Array (ALMA) 870 μm observations with simulated synthesis images of the two sources. The simulated images are based on a simple model containing a single, hot compact first-core-like component at the center surrounded by a large-scale, cold and dusty envelope described by a broken power-law density distribution with an index, α. Our results show that the hot compact components of B1-bN and B1-bS can be described by temperatures of ∼500 K with a size of ∼4 au, which are in agreement with theoretical predictions of an FHC. If the α inside the broken radii is fixed to −1.5, we find α ∼−2.9 and ∼−3.3 outside the broken radii for B1-bN and B1-bS, respectively, consistent with theoretical calculations of a collapsing, bounded envelope and previous observations. Comparing the density and temperature profiles of the two sources with radiation-hydrodynamic simulations of an FHC, we find both sources lie close to, but before, the second collapse stage. We suggest that B1-bS may have started the collapsing process earlier compared to B1-bN, since a larger discontinuity point is found in its density profile.
SPT-CL J2215−3537: A Massive Starburst at the Center of the Most Distant Relaxed Galaxy Cluster
Authors: Calzadilla Michael S. , Bleem Lindsey E. , McDonald Michael , Gladders Michael D. , Mantz Adam B. , Allen Steven W. , Bayliss Matthew B. , Eilers Anna-Christina , Floyd Benjamin , Hlavacek-Larrondo Julie , Khullar Gourav , Kim Keunho J. , Mahler Guillaume , Sharon Keren , Somboonpanyakul Taweewat , Stalder Brian , Stark Antony A. ,   SPT collaboration
Published: April 2023

Abstract
We present the discovery of the most distant, dynamically relaxed cool core cluster, SPT-CL J2215−3537 (SPT2215), and its central brightest cluster galaxy (BCG) at z = 1.16. Using new X-ray observations, we demonstrate that SPT2215 harbors a strong cool core with a central cooling time of 200 Myr (at 10 kpc) and a maximal intracluster medium cooling rate of 1900 ± 400 M
⊙ yr−1. This prodigious cooling may be responsible for fueling the extended, star-forming filaments observed in Hubble Space Telescope imaging. Based on new spectrophotometric data, we detect bright [O ii] emission in the BCG, implying an unobscured star formation rate (SFR) of

320

−
140

+
230

M
⊙ yr−1. The detection of a weak radio source (2.0 ± 0.8 mJy at 0.8 GHz) suggests ongoing feedback from an active galactic nucleus (AGN), though the implied jet power is less than half the cooling luminosity of the hot gas, consistent with cooling overpowering heating. The extreme cooling and SFR of SPT2215 are rare among known cool core clusters, and it is even more remarkable that we observe these at such high redshift, when most clusters are still dynamically disturbed. The high mass of this cluster, coupled with the fact that it is dynamically relaxed with a highly isolated BCG, suggests that it is an exceptionally rare system that must have formed very rapidly in the early universe. Combined with the high SFR, SPT2215 may be a high-z analog of the Phoenix cluster, potentially providing insight into the limits of AGN feedback and star formation in the most massive galaxies.
GALLIFRAY—A Geometric Modeling and Parameter Estimation Framework for Black Hole Images Using Bayesian Techniques
Authors: Saurabh  , Nampalliwar Sourabh 
Published: April 2023

Abstract
Recent observations of the galactic centers of M87 and the Milky Way with the Event Horizon Telescope have ushered in a new era of black-hole-based tests of fundamental physics using very long baseline interferometry (VLBI). Since it is a nascent field, there are several different modeling and analysis approaches in vogue (e.g., geometric and physical models, visibility and closure amplitudes, agnostic and multimessenger priors). We present GALLIFRAY, an open-source, Python-based framework for estimation/extraction of parameters using VLBI data. It is developed with modularity, efficiency, and adaptability as the primary objectives. This article outlines the design and usage of GALLIFRAY. As an illustration, we fit a geometric and a physical model to simulated data sets using Markov Chain Monte Carlo sampling and find good convergence of the posterior distribution. We conclude with an outline of further enhancements currently in development.
Calibration Target Selection for the SPARCS Satellite
Authors: Frymire Alexandra , Ardila David 
Published: April 2023

Abstract
The Star–Planet Activity Research CubeSat (SPARCS) is an upcoming NASA mission to understand the impact of low-mass stellar radiation on exoplanets. SPARCS will obtain photometric observations of low-mass stars in two bands: 153–171 nm (Far-UV; FUV) and 258–308 nm (Near-UV; NUV). SPARCS’ absolute calibration will be derived by observing White Dwarfs (WDs). WD selected as SPARCS calibrators should vary ≤7%. Here we present a study of UV variability of potential WD calibrators, based on Galaxy Evolution Explorer and HST/UVIS photometric observations. We collected data on a sample of 29 WDs from the Mikulski Archive for Space Telescopes and identified 8 potential SPARCS calibration targets in the NUV and 5 in the FUV, for a total of 10 distinct targets. Statistical analysis shows variability <3% in both bands. For some stars, the intrinsic astrophysical variability is smaller than these limits.
Diffusion Coefficients of 56Fe in C–O and O–Ne White Dwarfs
Authors: Caplan Matthew E. 
Published: April 2023

Abstract
The diffusion coefficients of neutron rich nuclei in crystallizing white dwarf (WD) stars are essential microphysics input for modeling the evolution of the composition profile. Recently, molecular dynamics simulations have been used to compute diffusion coefficients for realistic mixtures of C–O and O–Ne WDs with many trace nuclides that could be important sedimentary heat sources such as 22Ne, 23Na, 25Mg, and 27Mg. In this brief note, I repeat these simulations but now include 56Fe. I find that for the large charge ratios involved in these mixtures the empirical law developed in our earlier work tends to under-predict diffusion coefficients in the moderately coupled regime by 30%–40%. As this formalism is presently implemented in the stellar evolution code MESA, it is important for authors studying mixtures containing heavy nuclides like 56Fe to be aware of these systematics. However, the impact on astrophysics is expected to be small.
APE2 Promotes AID-Dependent Somatic Hypermutation in Primary B Cell Cultures That Is Suppressed by APE1
Authors: Schrader Carol E , Williams Travis , Pechhold Klaus , Linehan Erin K , Tsuchimoto Daisuke , Nakabeppu Yusaku 
Published: April 2023

Abstract
Somatic hypermutation (SHM) is necessary for Ab diversification and involves error-prone DNA repair of activation-induced cytidine deaminase–induced lesions in germinal center (GC) B cells but can also cause genomic instability. GC B cells express low levels of the DNA repair protein apurinic/apyrimidinic (AP) endonuclease (APE)1 and high levels of its homolog APE2. Reduced SHM in APE2-deficient mice suggests that APE2 promotes SHM, but these GC B cells also exhibit reduced proliferation that could impact mutation frequency. In this study, we test the hypothesis that APE2 promotes and APE1 suppresses SHM. We show how APE1/APE2 expression changes in primary murine spleen B cells during activation, impacting both SHM and class-switch recombination (CSR). High levels of both APE1 and APE2 early after activation promote CSR. However, after 2 d, APE1 levels decrease steadily with each cell division, even with repeated stimulation, whereas APE2 levels increase with each stimulation. When GC-level APE1/APE2 expression was engineered by reducing APE1 genetically (apex1+/−) and overexpressing APE2, bona fide activation-induced cytidine deaminase–dependent VDJH4 intron SHM became detectable in primary B cell cultures. The C terminus of APE2 that interacts with proliferating cell nuclear Ag promotes SHM and CSR, although its ATR-Chk1–interacting Zf-GRF domain is not required. However, APE2 does not increase mutations unless APE1 is reduced. Although APE1 promotes CSR, it suppresses SHM, suggesting that downregulation of APE1 in the GC is required for SHM. Genome-wide expression data compare GC and cultured B cells and new models depict how APE1 and APE2 expression and protein interactions change during B cell activation and affect the balance between accurate and error-prone repair during CSR and SHM.
The Majority of the Serine/Threonine Phosphorylation Sites in Bcl11b Protein Are Dispensable for the Differentiation of T Cells
Authors: Okuyama Kazuki , Nomura Aneela , Nishino Kohei , Tanaka Hirokazu , Harly Christelle , Chihara Risa , Harada Yasuyo , Muroi Sawako , Kubo Masato , Kosako Hidetaka , Taniuchi Ichiro 
Published: April 2023

Abstract
Posttranslational modification, such as phosphorylation, is an important biological event that modulates and diversifies protein function. Bcl11b protein is a zinc-finger transcription factor that plays a crucial role in early T cell development and the segregation of T cell subsets. Bcl11b possesses at least 25 serine/threonine (S/T) residues that can be phosphorylated upon TCR stimulation. To understand the physiological relevance of the phosphorylation on Bcl11b protein, we replaced S/T residues with alanine (A) by targeting murine Bcl11b gene in embryonic stem cells. By combinational targeting of exons 2 and 4 in the Bcl11b gene, we generated a mouse strain, Bcl11b-phosphorylation site mutation mice, in which 23 S/T residues were replaced with A residues. Such extensive manipulation left only five putative phosphorylated residues, two of which were specific for mutant protein, and resulted in reduced amounts of Bcl11b protein. However, primary T cell development in the thymus, as well as the maintenance of peripheral T cells, remained intact even after loss of major physiological phosphorylation. In addition, in vitro differentiation of CD4+ naive T cells into effector Th cell subsets—Th1, Th2, Th17, and regulatory T—was comparable between wild-type and Bcl11b-phosphorylation site mutation mice. These findings indicate that the physiological phosphorylation on major 23 S/T residues in Bcl11b is dispensable for Bcl11b functions in early T cell development and effector Th cell differentiation.
Natural Microbial Exposure from the Earliest Natural Time Point Enhances Immune Development by Expanding Immune Cell Progenitors and Mature Immune Cells
Authors: Burger Sarah , Stenger Terran , Pierson Mark , Sridhar Adhvaith , Huggins Matthew A , Kucaba Tamara A , Griffith Thomas S , Hamilton Sara E , Schuldt Nathaniel J 
Published: April 2023

Abstract
Microbial experience fundamentally shapes immunity, particularly during the perinatal period when the immune system is underdeveloped, and novel microbial encounters are common. Most animal models are raised in specific pathogen-free (SPF) conditions with relatively uniform microbial communities. How SPF housing conditions alter early-life immune development relative to natural microbial exposure (NME) has not been thoroughly investigated. In this article, we compare immune development in SPF-raised mice with mice born from immunologically experienced mothers in microbially diverse environments. NME induced broad immune cell expansion, including naive cells, suggesting mechanisms besides activation-induced proliferation contribute to the increase in immune cell numbers. We found NME conditions also expanded immune cell progenitor cell populations in the bone marrow, suggesting microbial experience enhances immune development at the earliest stages of immune cell differentiation. Multiple immune functions characteristically impaired in infants were also enhanced by NME, including T cell memory and Th1 polarization, B cell class switching and Ab production, proinflammatory cytokine expression, and bacterial clearance after Listeria monocytogenes challenge. Collectively, our studies reveal numerous impairments in immune development in SPF conditions relative to natural immune development.
The long-run effects of health aid in low-income countries
Authors: Negeri Keneni G. 
Published: April 2023

Background: Whether health aid has a positive, negative, or no effect on the health status of recipient countries is controversial.Objective: The current paper examines the long-run effect of health aid on health status in low-income countries.Methods: The long-run health function was estimated using infant mortality as a proxy for health status and panel data constructed from 34 low-income countries from 2000 to 2017. For the estimation, fixed effect, random effect, and Hausman-Taylor estimators were employed.Results: The estimation results indicate that health aid has a beneficial and statistically significant long-run effect on the health status of low-income countries. Doubling health aid saves the lives of 44 infants per 1000 live births in the long run.Conclusion: This study shows that health aid could be one of the best interim tools with which the health status of low-income groups could get improved and helps meet the target of universal health coverage. Despite the favorable effect of health aid observed in this study, recipient countries need to find ways of promoting surrogate domestic health financing systems, as external assistance cannot be an everlasting means of improving population health.
Myositis and rhabdomyolysis in scrub typhus infection
Authors: Bolla Tukaram , Bhattarai Sushmita , Singh Harpreet , Suri Vikas , Bhalla Ashish , Chatterjee Debajyoti 
Published: April 2023

Rationale:
Fever with myositis and rhabdomyolysis is a medical emergency requiring prompt diagnosis and management. Scrub typhus associated myositis with rhabdomyolysis is rare.

Patient concerns:
A 36-year-old female presented with intermittent fever up to 38.6 °C, jaundice and progressive weakness of all four limbs.

Diagnosis:
Scrub typhus associated myositis and rhabdomyolysis.

Intervention:
Doxycycline 100 mg twice daily and injection of ceftriaxone 1 gm twice daily along with continuous intravenous fluids.

Outcome:
Fever resolved with normalization of liver function and recovery of muscle power.

Lessons:
Presence of myositis and rhabdomyolysis is uncommon in scrub typhus; high clinical suspicion should be kept in patients with atypical manifestations of scrub typhus.
Mental Health Problems in Health-Care Workers of Tertiary Level COVID-19 Care Centers in Central India
Authors: Mahajan Sudhir Laludeo , Saraf Anantprakash Siddharthkumar , Sathe Harshal Shriram , Mishra Kshirod Kumar , John Sally , Reshamvala Ahmed Mushtaq 
Published: April 2023

Background:
The health-care workers (HCWs) who are overburdened during the COVID-19 pandemic are at increased risk of developing psychological disorders.

Aim:
The aim of this study was to assess the magnitude of psychological problems such as depression, anxiety, and fear of COVID-19 among the HCWs and to study their correlates. Material and Methods: The study is an online multicentric cross-sectional survey of mental health problems in the HCWs of three tertiary level COVID care centers in Central India. HCWs were assessed using the Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder Scale-7 (GAD-7), and Fear of COVID-19 Scale.

Results:
Out of 467 HCWs assessed, 25.5% of the participants had depression (defined by PHQ-9 score of more than 5), whereas anxiety was present in 24.4% of the study subjects (defined by GAD-7 score of more than 5). Forty-six percent of the participants had medium-to-high levels of fear of COVID-19. Female gender, working in the nonclinical department, direct involvement in care of COVID-19 patients, perceived worsening of physical health status following the pandemic outbreak, and past history of psychiatric problem were the factors significantly associated with presence of depression as well as anxiety. Age of the participant had a positive correlation with fear of COVID-19 and a negative correlation with depression and anxiety levels.

Conclusion:
HCWs serving in COVID hospitals are vulnerable to develop mental health problems and appropriate screening measures and interventions should be designed so as to preserve mental health of this vital task force.
An Exploratory Survey on the Knowledge, Attitudes, and Perceptions toward TikTok
Authors: Shah Bhumika , Karia Sagar , Mandalia Bilvesh , Shah Nilesh , Sousa Avinash De 
Published: April 2023

Background:
TikTok is a mobile application that had become very popular among youth in college and adults alike. Many people have used TikTok as an alternate form of social media and share videos from there on different social media platforms. This study was aimed as survey to ascertain the knowledge, attitudes, and practices toward TikTok as an application.

Methodology:
A semi-structured questionnaire was prepared to consist of questions regarding demographic details, knowledge regarding TikTok, frequency of usage of TikTok, attitudes toward its use and suggestions for change required in it. The questionnaire was circulated among students through e-mails and Whatsapp. The form was distributed three times in all within a gap of 7 days. The data collected were subjected to descriptive statistical analysis and percentages.

Results:
Seven hundred students in all were mailed and received the questionnaire. We received 583 responses, of which 81 responses being incomplete were removed, and the final analysis was done with 502 responses. Three hundred and three (60.4%) participants felt that it could be used for entertainment and only 11 (2.2%) mentioned education or awareness. Two hundred and seventy-two (54.2%) participants felt that TikTok use could be a media for boosting self-esteem and self-image.

Conclusion:
Further studies in detail about various facets of TikTok need to be studied in diverse population to generalize our findings and know how this application has influenced the youth in various sectors.
Depression Anxiety and Stress in Patients Visiting Medicine Outpatient Department of Tertiary Care Hospital During COVID Pandemic
Authors: Zain  , Datar Manjiri Chaitanya , Shetty Jyoti Vittaldas 
Published: April 2023

Background:
Coronavirus disease 2019 is a unique pandemic that has struck all the nations. Extraordinary crisis warrants extraordinary response like severe lockdown. The study aims to assess the prevalence of depression, anxiety, and stress, in general, and around corona, in particular, in people with medical comorbidity.

Setting and Design:
This is a cross-sectional study that was carried out in outpatient department setting of a tertiary care hospital from July 2020 to September 2020.

Aims and Objectives:
The study aimed to assess the prevalence of depression, anxiety, and stress, in general, and anxiety around corona, in particular, and the correlation with sociodemographic profile and comorbid medical illness.

Materials and Methods:
Fifty patients with various medical comorbidities were assessed using depression anxiety and stress scale and corona anxiety scale (CAS) and a specially designed pro forma.

Statistical Analysis:
The collected data were coded and entered in Microsoft Excel sheet. The data were analyzed using Statistical Packages for the Social Sciences version 20.0 software. The results are presented in a tabular and graphical format. For quantitative data, mean, standard deviation, median, etc., were calculated. For qualitative data, various frequency, rates, ratio, and percentage were calculated.

Results:
A statistically significant relationship was found between education and anxiety (P = 0.027) and between medical comorbidity and depression.

Conclusion:
In our study, medical comorbidities are associated with depressive cognition. Surprisingly, no significant anxiety on CAS could be found.