bluuebunny/crossref_metadata_2025_split huggingface dataset:
Discovery of magnetic fields along stacked cosmic filaments as revealed by radio and X-ray emission
Authors: Vernstrom T , Heald G , Vazza F , Galvin T J , West J L , Locatelli N , Fornengo N , Pinetti E 
Published: May 2021

ABSTRACT
Diffuse filaments connect galaxy clusters to form the cosmic web. Detecting these filaments could yield information on the magnetic field strength, cosmic ray population, and temperature of intercluster gas; yet, the faint and large-scale nature of these bridges makes direct detections very challenging. Using multiple independent all-sky radio and X-ray maps we stack pairs of luminous red galaxies as tracers for cluster pairs. For the first time, we detect an average surface brightness between the clusters from synchrotron (radio) and thermal (X-ray) emission with ≳5σ significance, on physical scales larger than observed to date (${\ge}3$ Mpc). We obtain a synchrotron spectral index of α ≃ −1.0 and estimates of the average magnetic field strength of $30\,\mathrm{ nG} \le B \le 60 $ nG, derived from both equipartition and inverse-Compton arguments, implying a 5–15 per cent degree of field regularity when compared with Faraday rotation measure estimates. While the X-ray detection is inline with predictions, the average radio signal comes out higher than predicted by cosmological simulations and dark matter annihilation and decay models. This discovery demonstrates that there are connective structures between mass concentrations that are significantly magnetized, and the presence of sufficient cosmic rays to produce detectable synchrotron radiation.
A multiline study of the filamentary infrared dark cloud G351.78–0.54
Authors: Ryabukhina O L , Zinchenko I I 
Published: May 2021

ABSTRACT
We present results of a multiline study of the filamentary infrared dark cloud G351.78–0.54 in the 1.3 and 0.8 mm wavelength bands. The lines of the three isotopologues of carbon monoxide CO, N2H+, CH3CCH, and HNCO were observed. The aim was to study the general structure of the filamentary cloud, its fragmentation, and physical parameters with the emphasis on properties of dense clumps in this cloud. Several dense clumps are identified from the N2H+ (3–2) data, their masses and virial parameters are determined using the C18O (2–1) line. Temperatures of some clumps are estimated from the CH3CCH and HNCO data. Almost all clumps appear to be gravitationally unstable. The density estimates obtained from the C18O (3–2)/(2–1) and N2H+ (3–2)/(1–0) intensity ratios are in the range n ∼ (0.3–3) × 105 cm−3. The HNCO emission is detected exclusively towards the first clump which contains the luminous IR source IRAS 17233–3606, and indicates an even higher density. It is observed in the outflow, too. The velocity shift of the higher excitation HNCO lines may indicate a movement of the hot core relative to the surrounding medium. In some clumps there is a velocity shift ∼1 km s−1 between N2H+ (3–2) and CO isotopologues. The large widths of the N2H+ (3–2) line in the clumps indicate an increase of the velocity dispersion in their dense interiors, which may be related to the star formation process. The N2H+ abundance drops towards the luminous IR source.
Interpreting the spectral lags of single-pulsed gamma-ray bursts via the photosphere in the jet model
Authors: Jiang Yun-Guo , Liu Ke-Xin , Shao Lang , Li Huai-Zhen 
Published: May 2021

ABSTRACT
The prompt emission of gamma-ray bursts (GRBs) is a long-standing problem. The spectral-lag phenomenon can provide us with some clues about the emission mechanism. By analogy with the spectral lag of blazars at radio frequencies, we propose using the photosphere in the jet model to interpret the spectral lag of GRBs. Assuming a canonical jet and respecting the scaling laws of both the magnetic field and the number density of radiative particles, the radius of the photosphere and the magnetic field can be predicted. Five long bursts with known redshifts are studied. The prompt emitting regions of these bursts are located at about one or several astronomical units from the jet base. Without strictly constrained parameters, the magnetic fields at the photosphere radius are not well constrained. Taking the median values, the magnetic field is distributed in the range of 104∼107 G, which has no conflicts with the constraints obtained from the synchrotron cooling time.
A randomized phase II trial of veliparib, radiotherapy, and temozolomide in patients with unmethylatedMGMTglioblastoma: the VERTU study
Authors: Sim Hao-Wen , McDonald Kerrie L , Lwin Zarnie , Barnes Elizabeth H , Rosenthal Mark , Foote Matthew C , Koh Eng-Siew , Back Michael , Wheeler Helen , Sulman Erik P , Buckland Michael E , Fisher Lauren , Leonard Robyn , Hall Merryn , Ashley David M , Yip Sonia , Simes John , Khasraw Mustafa 
Published: May 2021

AbstractBackgroundTemozolomide offers minimal benefit in patients with glioblastoma with unmethylated O6-methylguanine-DNA methyltransferase (MGMT) promoter status, hence, the need for novel therapies. This study evaluated whether veliparib, a brain-penetrant poly(ADP-ribose) polymerase (PARP) inhibitor, acts synergistically with radiation and temozolomide.MethodsVERTU was a multicenter 2:1 randomized phase II trial in patients with newly diagnosed glioblastoma and MGMT-unmethylated promotor status. The experimental arm consisted of veliparib and radiotherapy, followed by adjuvant veliparib and temozolomide. The standard arm consisted of concurrent temozolomide and radiotherapy, followed by adjuvant temozolomide. The primary objective was to extend the progression-free survival rate at six months (PFS-6m) in the experimental arm.ResultsA total of 125 participants were enrolled, with 84 in the experimental arm and 41 in the standard arm. The median age was 61 years, 70% were male, 59% had Eastern Cooperative Oncology Group (ECOG) performance status of 0, and 87% underwent macroscopic resection. PFS-6m was 46% (95% confidence interval [CI]: 36%-57%) in the experimental arm and 31% (95% CI: 18%-46%) in the standard arm. Median overall survival was 12.7 months (95% CI: 11.4-14.5 months) in the experimental arm and 12.8 months (95% CI: 9.5-15.8 months) in the standard arm. The most common grade 3-4 adverse events were thrombocytopenia and neutropenia, with no new safety signals.ConclusionThe veliparib-containing regimen was feasible and well tolerated. However, there was insufficient evidence of clinical benefit in this population. Further information from correlative translational work and other trials of PARP inhibitors in glioblastoma are still awaited.
Predictors of Academic Neurosurgical Career Trajectory among International Medical Graduates Training Within the United States
Authors: Khalafallah Adham M , Jimenez Adrian E , Camp Samantha , Horowitz Melanie A , Chiu Ian , Ryu David , Charewycz Natasha , Vera Lauren , Bhoopalam Myan , Feghali James , Sharma Mayur , Lubelski Daniel , Cohen Alan R , Tamargo Rafael J , Witham Timothy , Huang Judy , Brem Henry , Mukherjee Debraj 
Published: May 2021

Abstract

BACKGROUND
Within the literature, there has been limited research tracking the career trajectories of international medical graduates (IMGs) following residency training.

OBJECTIVE
To compare the characteristics of IMG and US medical school graduate (USMG) neurosurgeons holding academic positions in the United States and also analyze factors that influence IMG career trajectories following US-based residency training.

METHODS
We collected data on 243 IMGs and 2506 USMGs who graduated from Accreditation Council for Graduate Medical Education (ACGME)-accredited neurosurgery residency programs. We assessed for significant differences between cohorts, and a logistic regression model was used for the outcome of academic career trajectory.

RESULTS
Among the 2749 neurosurgeons in our study, IMGs were more likely to pursue academic neurosurgery careers relative to USMGs (59.7% vs 51.1%; P = .011) and were also more likely to complete a research fellowship before beginning residency (odds ratio [OR] = 9.19; P < .0001). Among current US academic neurosurgeons, USMGs had significantly higher pre-residency h-indices relative to IMGs (1.23 vs 1.01; P < .0001) with no significant differences between cohorts when comparing h-indices during (USMG = 5.02, IMG = 4.80; P = .67) or after (USMG = 14.05, IMG = 13.90; P = .72) residency. Completion of a post-residency clinical fellowship was the only factor independently associated with an academic career trajectory among IMGs (OR = 1.73, P = .046).

CONCLUSION
Our study suggests that while IMGs begin their US residency training with different research backgrounds and achievements relative to USMG counterparts, they attain similar levels of academic productivity following residency. Furthermore, IMGs are more likely to pursue academic careers relative to USMGs. Our work may be useful for better understanding IMG career trajectories following US-based neurosurgery residency training.
Beyond Strong Enforcement: Understanding the Factors Related to Retailer Compliance With Tobacco 21
Authors: Roberts Megan E , Klein Elizabeth G , Ferketich Amy K , Keller-Hamilton Brittney , Berman Micah L , Chacko Michael , Jenkins Claire F , Segall Morgan H , Woodyard Kiersten C 
Published: May 2021

Abstract

Introduction
Tobacco 21 (T21), which sets the minimum legal sales age for tobacco to age 21, is now a national law in the United States. Although T21 is expected to help curb youth tobacco use, its impact may be dampened due to poor retailer compliance. Even within environments where enforcement is strong (ie, compliance checks are conducted with tough sanctions for violations), compliance might vary due to other factors.

Aims and Methods
Three studies were conducted in Columbus, OH, where T21 became strongly enforced in 2018. These studies examined how retailer compliance related to features of the neighborhood in which a retailer was located (Study 1), features of the retailer (Study 2), and features of the retail cashier (Study 3).

Results
Study 1 found that, after controlling for race- and age-based factors, retailers located in high (vs. low)-poverty neighborhoods had a lower likelihood of conducting identification (ID) checks. Study 2 found that ID checks were related to whether retailers displayed signage about T21, as required by the city law. Study 3 found that, among cashiers, T21 awareness (which was high) and perceptions about T21 (which were moderate) were not generally related to their retailer’s compliance; having (vs. not having) scanners for ID checks was related to a higher likelihood of compliance.

Conclusions
These studies emphasize the many, multilevel factors influencing T21 outcomes. Findings also indicate the potential for T21 to widen disparities in tobacco use, indicating the need for strategies to equitably improve T21 compliance.

Implications
T21, which sets the minimum legal sales age for all tobacco products to age 21, is now a national law in the United States. Despite optimistic projections about what T21 could achieve, the ultimate impact may be dampened when it is applied in real-world settings. Our project revealed the many, multilevel factors influencing T21 compliance. Findings also indicate the potential for T21 to widen disparities in tobacco use if gaps in compliance persist. Strategies for equitably improving T21 compliance are discussed. This article is of relevance to areas interested in implementing or improving their local T21 enforcement.
Multiple lines of evidence indicate ongoing allopatric and parapatric diversification in an Afromontane sunbird (Cinnyris reichenowi)
Authors: Cooper Jacob C , Maddox J Dylan , McKague Kellie , Bates John M 
Published: May 2021

Abstract
Africa’s montane ecosystems are noteworthy not only for their isolation but for their morphologically similar bird populations that inhabit geographically disparate localities. Many species possess range disjunctions in excess of 2,000 km and appear to represent populations that have been isolated since at least the last Ice Age, including the Northern Double-collared Sunbird (Cinnyris reichenowi). Recent work on other Afromontane birds has demonstrated substantial phylogeographic structure can exist in phenotypically similar populations, with cryptic species occurring parapatrically within the same mountain range. We explored genetic, morphological, and ecological diversity within C. reichenowi to assess whether cryptic regional diversification occurs across the disjunct portions of this species’ range. Within C. reichenowi, we find consistent patterns of morphological disparity that coincide with genetic diversification between xeric and wet montane populations within the Cameroon Line in the Western population, and clear genetic differentiation between Western and Eastern populations. Our research demonstrates that the geographically isolated populations of C. reichenowi represent different species, and that ecological diversification is shaping populations within Central Africa. We show here that two named populations should be recognized as members of a western species in the Northern Double-collared Sunbird complex: nominate Cinnyris preussi preussi in the Cameroon Line montane forests, and Cinnyris preussi genderuensis in the more xeric interior of Cameroon and the Central African Republic, likely occurring in adjacent Nigeria as well.
Bringing Social Context Back In
Authors: Carlsen Hjalmar Bang , ToubØl Jonas , Ralund Snorre 
Published: May 2021

AbstractThis article demonstrates the utility of combining individual survey data with social media content data in order to analyze how social context predicts individual behavior. The lack of valid and reliable measures of the contexts of social interaction in which individuals are embedded has remained an Achilles heel of the survey method. The reason is that the collection of direct observation of social interaction requires qualitative analysis of the context, which, hitherto, has been too costly to collect on a large scale. Instead, researchers have resorted to indirect measures such as aggregate group composition, respondent reports of social context, and institutional accounts. However, with the recent advent of social media data, contemporary social scientists now have social interaction data on an unprecedented scale. To utilize these data for quantitative analysis, researchers have to transform text prose into good measurement. We combine qualitative content analysis and supervised machine learning in order to ensure both semantic validity and accuracy in our measure of social interaction in Facebook groups. To test the substantive performance of the direct measures of social interaction, we use it to predict individual participation in refugee solidarity activism in Denmark. Additional testing indicates that the direct measure cannot easily be replaced by indirect measures of social interaction derived from group composition and institutional accounts. We also show how contexts and individual respondents can be effectively sampled using Facebook groups. Finally, the article discusses the limitations of social media data and points to alternate settings where our design is applicable.
Corona doubt and scepticism: repression and denial as psychological defence mechanisms to process distress?
Authors: Teufel Martin , Schweda Adam , Kohler Hannah , Musche Venja , Fink Madeleine , Weismüller Benjamin , Moradian Sheila , Skoda Eva-Maria , Bäuerle Alexander 
Published: May 2021

Abstract
After more than a year of pandemic, SARS-CoV-2 (Severe acute respiratory syndrome coronavirus type 2) remains a relevant health care and society issue. Movements doubting the dangerousness or the existence of the virus have emerged and became a challenge to social cohesion. About 3487 individuals (434 Corona doubters and 3053 non-doubters) have participated in an online survey (predominat age group: 35–45 years). Particularly, COVID-19-related anxiety, generalized anxiety (Generalizied Anxiety Disorder Screener, GAD-7), depression (Patient Health Questionnaire, PHQ-2) and functional/adherent safety behaviour were assessed. COVID-19 doubters describe less functional safety behaviour. Fear of the virus is evident, similar to non-doubters. Generalized anxiety and depression were significantly higher in doubters. Repression and denial as psychological defence mechanisms could be the unconscious psychological strategy for coping with the distress variables. The results point out that public strategies may only be successful in managing opinions and beliefs if they address fears and worries.
Isolated IgG2 deficiency is an independent risk factor for exacerbations in bronchiectasis
Authors: Zhang Y , Clarke A , Regan K H , Campbell K , Donaldson S , Crowe J , Rossi A G , Hill A T 
Published: May 2021

Summary

Background
Immunoglobulin G (IgG) subclass 2 deficiency is the most frequent IgG subclass deficiency identified in patients with bronchiectasis, but its clinical significance is not known.

Aim
To analyse if bronchiectasis patients with isolated IgG2 deficiency at risk of recurrent exacerbations and/or hospitalization? Do patients with IgG2 deficiency have worse disease progression?

Design and Methods
This is a retrospective study (2015–20) exploring independent risk factors for recurrent exacerbations (3 or more per year) and/or hospitalization with bronchiectasis exacerbations using multivariable models using binary logistic regression. There was no patient with IgG deficiency, IgG 1, 3 or 4 deficiency, or IgA or IgM deficiency included. In this model, the authors included: serum IgG2 level; lung function; body mass index; MRC breathlessness scale; age; sex; number of bronchiectatic lobes; bacterial colonization; comorbidities; and the use of long-term immunosuppressant drugs or antibiotics for more than 28 days. Analysing 2-year longitudinal data, one-way ANOVA and Mann–Whitney U-test were used to compare bronchiectasis severity between patients with different IgG2 levels.

Results
Serum IgG2 levels (&lt;2.68 g/l, 2.68–3.53 g/l and 3.54–4.45 g/l); hospital admission in the preceding 2 years; bacterial colonization with potentially pathogenic organisms and asthma were independent predictors for three or more bronchiectasis exacerbations. Those with low IgG2 levels (&lt;2.68 g/l and 2.68–3.53 g/l), had worsening progression of their bronchiectasis, using the Bronchiectasis Severity Index, over 1 year compared with those who were IgG2 replete (&gt;4.45 g/l) (P = 0.003, 0.013).

Conclusion
Reduced IgG2 levels were an independent predictor for bronchiectasis exacerbations and have increased disease progression.
Obesity as a Risk Factor for Accelerated Brain Ageing in First-Episode Psychosis—A Longitudinal Study
Authors: McWhinney Sean , Kolenic Marian , Franke Katja , Fialova Marketa , Knytl Pavel , Matejka Martin , Spaniel Filip , Hajek Tomas 
Published: May 2021

Abstract

Background
Obesity is highly prevalent in schizophrenia, with implications for psychiatric prognosis, possibly through links between obesity and brain structure. In this longitudinal study in first episode of psychosis (FEP), we used machine learning and structural magnetic resonance imaging (MRI) to study the impact of psychotic illness and obesity on brain ageing/neuroprogression shortly after illness onset.

Methods
We acquired 2 prospective MRI scans on average 1.61 years apart in 183 FEP and 155 control individuals. We used a machine learning model trained on an independent sample of 504 controls to estimate the individual brain ages of study participants and calculated BrainAGE by subtracting chronological from the estimated brain age.

Results
Individuals with FEP had a higher initial BrainAGE than controls (3.39 ± 6.36 vs 1.72 ± 5.56 years; β = 1.68, t(336) = 2.59, P = .01), but similar annual rates of brain ageing over time (1.28 ± 2.40 vs 1.07±1.74 estimated years/actual year; t(333) = 0.93, P = .18). Across both cohorts, greater baseline body mass index (BMI) predicted faster brain ageing (β = 0.08, t(333) = 2.59, P = .01). For each additional BMI point, the brain aged by an additional month per year. Worsening of functioning over time (Global Assessment of Functioning; β = −0.04, t(164) = −2.48, P = .01) and increases especially in negative symptoms on the Positive and Negative Syndrome Scale (β = 0.11, t(175) = 3.11, P = .002) were associated with faster brain ageing in FEP.

Conclusions
Brain alterations in psychosis are manifest already during the first episode and over time get worse in those with worsening clinical outcomes or higher baseline BMI. As baseline BMI predicted faster brain ageing, obesity may represent a modifiable risk factor in FEP that is linked with psychiatric outcomes via effects on brain structure.
Gene Flow Increases Phylogenetic Structure and Inflates Cryptic Species Estimations: A Case Study on Widespread Philippine Puddle Frogs (Occidozyga laevis)
Authors: Chan Kin Onn , Hutter Carl R , Wood Perry L , Su Yong-Chao , Brown Rafe M 
Published: May 2021

AbstractIn cryptic amphibian complexes, there is a growing trend to equate high levels of genetic structure with hidden cryptic species diversity. Typically, phylogenetic structure and distance-based approaches are used to demonstrate the distinctness of clades and justify the recognition of new cryptic species. However, this approach does not account for gene flow, spatial, and environmental processes that can obfuscate phylogenetic inference and bias species delimitation. As a case study, we sequenced genome-wide exons and introns to evince the processes that underlie the diversification of Philippine Puddle Frogs—a group that is widespread, phenotypically conserved, and exhibits high levels of geographically based genetic structure. We showed that widely adopted tree- and distance-based approaches inferred up to 20 species, compared to genomic analyses that inferred an optimal number of five distinct genetic groups. Using a suite of clustering, admixture, and phylogenetic network analyses, we demonstrate extensive admixture among the five groups and elucidate two specific ways in which gene flow can cause overestimations of species diversity: 1) admixed populations can be inferred as distinct lineages characterized by long branches in phylograms; and 2) admixed lineages can appear to be genetically divergent, even from their parental populations when simple measures of genetic distance are used. We demonstrate that the relationship between mitochondrial and genome-wide nuclear $p$-distances is decoupled in admixed clades, leading to erroneous estimates of genetic distances and, consequently, species diversity. Additionally, genetic distance was also biased by spatial and environmental processes. Overall, we showed that high levels of genetic diversity in Philippine Puddle Frogs predominantly comprise metapopulation lineages that arose through complex patterns of admixture, isolation-by-distance, and isolation-by-environment as opposed to species divergence. Our findings suggest that speciation may not be the major process underlying the high levels of hidden diversity observed in many taxonomic groups and that widely adopted tree- and distance-based methods overestimate species diversity in the presence of gene flow. [Cryptic species; gene flow; introgression; isolation-by-distance; isolation-by-environment; phylogenetic network; species delimitation.]