bluuebunny/crossref_metadata_2025 huggingface dataset:
Tra1 controls the transcriptional landscape of the aging cell
Authors: Bari Khaleda Afrin , Berg Matthew D , Genereaux Julie , Brandl Christopher J , Lajoie Patrick
Published: October 2022

Gene expression undergoes considerable changes during the aging process. The mechanisms regulating the transcriptional response to cellular aging remain poorly understood. Here, we employ the budding yeast Saccharomyces cerevisiae to better understand how organisms adapt their transcriptome to promote longevity. Chronological lifespan assays in yeast measure the survival of nondividing cells at stationary phase over time, providing insights into the aging process of postmitotic cells. Tra1 is an essential component of both the yeast Spt-Ada-Gcn5 acetyltransferase/Spt-Ada-Gcn5 acetyltransferase-like and nucleosome acetyltransferase of H4 complexes, where it recruits these complexes to acetylate histones at targeted promoters. Importantly, Tra1 regulates the transcriptional response to multiple stresses. To evaluate the role of Tra1 in chronological aging, we took advantage of a previously characterized mutant allele that carries mutations in the TRA1 PI3K domain (tra1Q3). We found that loss of functions associated with tra1Q3 sensitizes cells to growth media acidification and shortens lifespan. Transcriptional profiling reveals that genes differentially regulated by Tra1 during the aging process are enriched for components of the response to stress. Notably, expression of catalases (CTA1, CTT1) involved in hydrogen peroxide detoxification decreases in chronologically aged tra1Q3 cells. Consequently, they display increased sensitivity to oxidative stress. tra1Q3 cells are unable to grow on glycerol indicating a defect in mitochondria function. Aged tra1Q3 cells also display reduced expression of peroxisomal genes, exhibit decreased numbers of peroxisomes, and cannot grow on media containing oleate. Thus, Tra1 emerges as an important regulator of longevity in yeast via multiple mechanisms.
Rat Mammary carcinoma susceptibility 3 (Mcs3) pleiotropy, socioenvironmental interaction, and comparative genomics with orthologous human 15q25.1-25.2
Authors: Duderstadt Emily L , Samuelson David J
Published: October 2022

Genome-wide association studies of breast cancer susceptibility have revealed risk-associated genetic variants and nominated candidate genes; however, the identification of causal variants and genes is often undetermined by genome-wide association studies. Comparative genomics, utilizing Rattus norvegicus strains differing in susceptibility to mammary tumor development, is a complimentary approach to identify breast cancer susceptibility genes. Mammary carcinoma susceptibility 3 (Mcs3) is a Copenhagen (COP/NHsd) allele that confers resistance to mammary carcinomas when introgressed into a mammary carcinoma susceptible Wistar Furth (WF/NHsd) genome. Here, Mcs3 was positionally mapped to a 7.2-Mb region of RNO1 spanning rs8149408 to rs107402736 (chr1:143700228–150929594, build 6.0/rn6) using WF.COP congenic strains and 7,12-dimethylbenz(a)anthracene-induced mammary carcinogenesis. Male and female WF.COP-Mcs3 rats had significantly lower body mass compared to the Wistar Furth strain. The effect on female body mass was observed only when females were raised in the absence of males indicating a socioenvironmental interaction. Furthermore, female WF.COP-Mcs3 rats, raised in the absence of males, did not develop enhanced lobuloalveolar morphologies compared to those observed in the Wistar Furth strain. Human 15q25.1-25.2 was determined to be orthologous to rat Mcs3 (chr15:80005820–82285404 and chr15:83134545–84130720, build GRCh38/hg38). A public database search of 15q25.1-25.2 revealed genome-wide significant and nominally significant associations for body mass traits and breast cancer risk. These results support the existence of a breast cancer risk-associated allele at human 15q25.1-25.2 and warrant ultrafine mapping of rat Mcs3 and human 15q25.1-25.2 to discover novel causal genes and variants.
Post-operative anastomotic leakage and collagen changes in patients with rectal cancer undergoing neoadjuvant chemotherapy vs chemoradiotherapy
Authors: Jiang Wei , Wang Huaiming , Zheng Jixiang , Zhao Yandong , Xu Shuoyu , Zhuo Shuangmu , Wang Hui , Yan Jun
Published: October 2022

Background

A significant difference in the anastomotic leakage (AL) rate has been observed between patients with locally advanced rectal cancer who have undergone preoperative chemotherapy and those undergoing preoperative chemoradiotherapy. This study aimed to quantitatively analyse collagen structural changes caused by preoperative chemoradiotherapy and illuminate the relationship between collagen changes and AL.

Methods

Anastomotic distal and proximal “doughnut” specimens from the Sixth Affiliated Hospital of Sun Yat-sen University (Guangzhou, China) were quantitatively assessed for collagen structural changes between patients with and without preoperative radiotherapy using multiphoton imaging. Then, patients treated with preoperative chemoradiotherapy were used as a training cohort to construct an AL–SVM classifier by the Mann–Whitney U test and support vector machine (SVM). An independent test cohort from the Fujian Province Cancer Hospital (Fuzhou, China) was used to validate the AL–SVM classifier.

Results

A total of 207 patients were included from the Sixth Affiliated Hospital of Sun Yat-sen University. The AL rate in the preoperative chemoradiotherapy group (n = 107) was significantly higher than that in the preoperative chemotherapy group (n = 100) (21.5% vs 7.0%, P = 0.003). A fully quantitative analysis showed notable morphological and spatial distribution feature changes in collagen in the preoperative chemoradiotherapy group. Then, the patients who received preoperative chemoradiotherapy were used as a training cohort to construct the AL–SVM classifier based on five collagen features and the tumor distance from the anus. The AL–SVM classifier showed satisfactory discrimination and calibration with areas under the curve of 0.907 and 0.856 in the training and test cohorts, respectively.

Conclusions

The collagen structure may be notably altered by preoperative radiotherapy. The AL–SVM classifier was useful for the individualized prediction of AL in rectal cancer patients undergoing preoperative chemoradiotherapy.
SARS-CoV-2 Serosurveys: How Antigen, Isotype and Threshold Choices Affect the Outcome
Authors: Binder Raquel A , Fujimori Gavin F , Forconi Catherine S , Reed George W , Silva Leandro S , Lakshmi Priya Saikumar , Higgins Amanda , Cincotta Lindsey , Dutta Protiva , Salive Marie-Claire , Mangolds Virginia , Anya Otuwe , Calvo Calle J Mauricio , Nixon Thomas , Tang Qiushi , Wessolossky Mireya , Wang Yang , Ritacco Dominic A , Bly Courtney S , Fischinger Stephanie , Atyeo Caroline , Oluoch Peter O , Odwar Boaz , Bailey Jeffrey A , Maldonado-Contreras Ana , Haran John P , Schmidt Aaron G , Cavacini Lisa , Alter Galit , Moormann Ann M
Published: October 2022

Background

Evaluating the performance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serological assays and clearly articulating the utility of selected antigens, isotypes, and thresholds is crucial to understanding the prevalence of infection within selected communities.

Methods

This cross-sectional study, implemented in 2020, screened PCR–confirmed coronavirus disease 2019 patients (n = 86), banked prepandemic and negative samples (n = 96), healthcare workers and family members (n = 552), and university employees (n = 327) for anti–SARS-CoV-2 receptor-binding domain, trimeric spike protein, and nucleocapsid protein immunoglobulin (Ig)G and IgA antibodies with a laboratory-developed enzyme-linked immunosorbent assay and tested how antigen, isotype and threshold choices affected the seroprevalence outcomes. The following threshold methods were evaluated: (i) mean + 3 standard deviations of the negative controls; (ii) 100% specificity for each antigen-isotype combination; and (iii) the maximal Youden index.

Results

We found vastly different seroprevalence estimates depending on selected antigens and isotypes and the applied threshold method, ranging from 0.0% to 85.4%. Subsequently, we maximized specificity and reported a seroprevalence, based on more than one antigen, ranging from 9.3% to 25.9%.

Conclusions

This study revealed the importance of evaluating serosurvey tools for antigen-, isotype-, and threshold-specific sensitivity and specificity, to interpret qualitative serosurvey outcomes reliably and consistently across studies.
Organizational and Technical Security Considerations for Laboratory Cloud Computing
Authors: Krumm Niklas
Published: October 2022

Background

Clinical and anatomical pathology services are increasingly utilizing cloud information technology (IT) solutions to meet growing requirements for storage, computation, and other IT services. Cloud IT solutions are often considered on the promise of low cost of entry, durability and reliability, scalability, and features that are typically out of reach for small- or mid-sized IT organizations. However, use of cloud-based IT infrastructure also brings additional security and privacy risks to organizations, as unfamiliarity, public networks, and complex feature sets contribute to an increased surface area for attacks.

Content

In this best-practices guide, we aim to help both managers and IT professionals in healthcare environments understand the requirements and risks when using cloud-based IT infrastructure within the laboratory environment. We will describe how technical, operational, and organizational best practices that can help mitigate security, privacy, and other risks associated with the use of could infrastructure; furthermore, we identify how these best practices fit into healthcare regulatory frameworks.

Among organizational best practices, we identify the need for specific hiring requirements, relationships with parent IT groups, mechanisms for reviewing and auditing security practices, and sound practices for onboarding and offboarding employees. Then, we highlight selected specific operational security, account security, and auditing/logging best practices. Finally, we describe how individual cloud technologies have specific resource-level security features.

We emphasize that laboratory directors, managers, and IT professionals must ensure that the fundamental organizational and process-based requirements are addressed first, to establish the groundwork for technical security solutions and successful implementation of cloud infrastructure.
Automated selection of changepoints using empirical P-values and trimming
Authors: Quinn Matthew , Chung Arlene , Glass Kimberly
Published: October 2022

Objectives

One challenge that arises when analyzing mobile health (mHealth) data is that updates to the proprietary algorithms that process these data can change apparent patterns. Since the timings of these updates are not publicized, an analytic approach is necessary to determine whether changes in mHealth data are due to lifestyle behaviors or algorithmic updates. Existing methods for identifying changepoints do not consider multiple types of changepoints, may require prespecifying the number of changepoints, and often involve nonintuitive parameters. We propose a novel approach, Automated Selection of Changepoints using Empirical P-values and Trimming (ASCEPT), to select an optimal set of changepoints in mHealth data.

Materials and Methods

ASCEPT involves 2 stages: (1) identification of a statistically significant set of changepoints from sequential iterations of a changepoint detection algorithm; and (2) trimming changepoints within linear and seasonal trends. ASCEPT is available at https://github.com/matthewquinn1/changepointSelect.

Results

We demonstrate ASCEPT’s utility using real-world mHealth data collected through the Precision VISSTA study. We also demonstrate that ASCEPT outperforms a comparable method, circular binary segmentation, and illustrate the impact when adjusting for changepoints in downstream analysis.

Discussion

ASCEPT offers a practical approach for identifying changepoints in mHealth data that result from algorithmic updates. ASCEPT’s only required parameters are a significance level and goodness-of-fit threshold, offering a more intuitive option compared to other approaches.

Conclusion

ASCEPT provides an intuitive and useful way to identify which changepoints in mHealth data are likely the result of updates to the underlying algorithms that process the data.
3M™ Petrifilm™ Rapid Yeast and Mold Count Plate for the Enumeration of Yeasts and Molds in Dried Cannabis Flower: AOACOfficial MethodSM 2014.05
Authors: Schumacher April , Lingle Cari , Silbernagel Karen M
Published: October 2022

Background

The 3MTM Petrifilm™ Rapid Yeast and Mold Count (RYM) Plate is a sample-ready culture medium system which contains nutrients supplemented with antibiotics, a cold-water-soluble gelling agent, and an indicator system that facilitates yeast and mold enumeration.

Objective

The 3M Petrifilm RYM Plate was validated for the enumeration of yeast and mold in dried cannabis flower through the AOAC Emergency Response Validation process.

Methods

The performance of the 3M Petrifilm RYM Plate was compared to dichloran rose bengal chloramphenicol (DRBC) agar. Matrix data were normalized by log10 transformation and performance indicators included repeatability, difference of means, and inclusivity/exclusivity.

Results

These studies demonstrated the 3M Petrifilm RYM Plate method detects and enumerates yeasts and molds from dried cannabis flower at low, medium, and high contamination levels. The average log counts at 25 or 28°C for 60 to 72 h were equivalent to the average log counts of the DRBC reference method at low, medium and high levels. In strain studies, all 71 yeasts and molds tested produced typical colony morphology on 3M Petrifilm RYM Plates. Of the 32 non-target bacterial strains tested, none were detected on 3M Petrifilm RYM Plates.

Conclusion

The 3M Petrifilm RYM Plate is a reliable method for the enumeration of live yeast and mold in dried cannabis flower.

Highlights

The 3M Petrifilm RYM Plate allows for rapid detection of yeast and mold within 60 to 72 h of incubation. Up to 40 sample-ready plates can be stacked during incubation to save space.
Constraining Tamil Transnational Political Action: Security Governance Practices beyond the Sending State
Authors: Craven Catherine Ruth
Published: October 2022

This paper examines the security governance of the Tamil diaspora through a practice lens. It takes as its starting point the observation that the Tamil diaspora community has historically been subjected to complex and multi-scalar security governance. How this continues after the end of the Sri Lankan civil war period remains empirically and theoretically underexamined, with studies focusing instead on Tamil diaspora organizing. This paper addresses this gap by mapping and theorizing contemporary constraints to Tamil transnational political action (TPA), building on the growing literature on the transnational repression of diaspora. Further, it proposes to move beyond the state-centrism and liberal bias inherent in this literature, by centering security governance practices. Based on a review of existing literature and historical and ethnographic data collected through mixed-method fieldwork among the Tamil diaspora community between 2015 and 2018, this paper concludes that key security governance practices that constrain Tamil TPA, such as proscription, counterterrorism policing, and formal diplomatic practices, have continued since the end of the civil war, each revealing complex global security entanglements beyond the diaspora sending state.
Social Determinants of Adherence to Treatment for Tuberculosis Infection and Disease Among Children, Adolescents, and Young Adults: A Narrative Review
Authors: Leddy Anna M , Jaganath Devan , Triasih Rina , Wobudeya Eric , Bellotti de Oliveira Marcia C , Sheremeta Yana , Becerra Mercedes C , Chiang Silvia S
Published: October 2022

Global efforts to eliminate tuberculosis (TB) must address the unique barriers that children (ages 0 through 9 years) and adolescents/young adults (AYA; ages 10 through 24 years) face in adhering to treatment for TB infection and disease. We conducted a narrative review to summarize current knowledge on the social determinants of treatment adherence among these age groups to guide efforts and policy to address their unique needs. Our findings revealed that research on TB treatment adherence among children and AYA is still in its nascent stage. The current literature revealed structural/community-, health system-, household-, and individual-level factors that influence treatment adherence and varied with developmental stage. There is a need to develop multilevel interventions to address the unique challenges that children and AYA face in adhering to TB treatment.
Tuberculosis in Children Living With HIV: Ongoing Progress and Challenges
Authors: Vonasek Bryan J , Rabie Helena , Hesseling Anneke C , Garcia-Prats Anthony J
Published: October 2022

There has been much recent progress on control of the tuberculosis (TB) and human immunodeficiency virus (HIV) epidemics globally. However, advances in children have lagged behind, and TB-HIV coinfection continues to be a major driver of pediatric mortality in many settings. This review highlights recent research findings in the areas of prevention, diagnosis, and treatment of HIV-associated childhood TB. Key areas for future research are defined. Current prevention efforts such as vaccination, TB symptom screening, and TB preventive treatment are demonstrated as beneficial but need to be optimized for children living with HIV (CLHIV). Diagnosis of HIV-associated TB in children remains a major challenge, depending heavily on clinicians’ ability to judge an array of signs, symptoms, and imaging findings, but there are a growing number of promising diagnostic tools with improved accuracy and feasibility. Treatment of TB-HIV coinfection has also seen recent progress with more evidence demonstrating the safety and effectiveness of shorter regimens for treatment of TB infection and disease and improved understanding of interactions between antiretrovirals and TB medications. However, several evidence gaps on drug-drug interactions persist, especially for young children and those with drug-resistant TB. Accelerated efforts are needed in these areas to build upon current progress and reduce the burden of TB on CLHIV.
Pediatric Tuberculosis Diagnostics: Present and Future
Authors: Basile Francesca Wanda , Nabeta Pamela , Ruhwald Morten , Song Rinn
Published: October 2022

The current diagnostic abilities for the detection of pediatric tuberculosis are suboptimal. Multiple factors contribute to the under-diagnosis of intrathoracic tuberculosis in children, namely the absence of pathognomonic features of the disease, low bacillary loads in respiratory specimens, challenges in sample collection, and inadequate access to diagnostic tools in high-burden settings. Nonetheless, the 2020s have witnessed encouraging progress in the area of novel diagnostics. Recent WHO-endorsed rapid molecular assays hold promise for use in service decentralization strategies, and new policy recommendations include stools as an alternative, child-friendly specimen for testing with the GeneXpert assay. The pipeline of promising assays in mid/late-stage development is expanding, and novel pediatric candidate biomarkers based on the host immune response are being identified for use in diagnostic and triage tests. For a new test to meet the pediatric target product profiles prioritized by the WHO, it is key that the peculiarities and needs of the hard-to-reach pediatric population are considered in the early planning phases of discovery, validation, and implementation studies.
Platelet aggregation with various morphologies of neutrophils in arterial thrombus in a patient with Coronavirus disease: a case report
Authors: Tanaka Chiharu , Hiraiwa Shinichiro , Otsuka Hiroyuki , Yamaguchi Masaomi
Published: October 2022

Arterial thromboembolism is a life-threatening condition in COVID-19 patients; however, the mechanism of hypercoagulopathy remains unknown. A 62-year-old man with a history of obesity was diagnosed with COVID-19 pneumonia. After hospitalisation, unfractionated heparin was administered because of increased D-dimer levels; nevertheless, an arterial embolism in the left lower limb developed on the following day. Enhanced computed tomography revealed an occluded left iliac artery and intra-aortic thrombus at the juxtarenal level. Urgent thrombectomy was performed. On post-operative day 6, coumadin was initiated to treat the remaining thrombus. The patient was discharged without any complications. The removed thrombus pathologically presented platelet aggregation and degenerated neutrophils that were in various time axes; some neutrophils had clear margins of nuclear membrane, whereas others had pyknotic and fragment nuclei. We believe that the platelet formation and the neutrophils in several time axes could be key factors in promoting thrombus formation in COVID-19 patients.
Sustainable Development Goals (SDG) indicators for municipalities: a comprehensive monitoring approach from Germany
Authors: Jossin Jasmin , Peters Oliver
Published: October 2022

While the 2030 agenda addresses the United Nation member states primarily at their national levels, municipalities play a crucial role in implementing all of the 17 SDGs and many of the 169 targets. These processes must be monitored and evaluated. However, the UN indicators are not sufficiently applicable to the local context. Therefore, a multi-stakeholder working group was formed in Germany to develop a comprehensive set of Sustainable Development Goal (SDG) indicators for municipalities, together with additional instruments to support local SDG monitoring such as an SDG data portal. The first catalogue which included 47 core SDG indicators was published in 2018. According to consecutive evaluations and practical tests, the indicator set was substantially expanded and revised to a final number of 120 SDG indicators. About half of the 120 indicators are provided with local-level data and the other half must be assessed individually for comprehensive local SDG monitoring. Likewise, accompanying tools were relaunched with additional functionalities. Although this new and unique set of indicators now covers a majority of the municipally relevant targets, there are still some decisive monitoring gaps for various reasons. The strengths and weaknesses of our methodological approach, as well as implications for future research and practical developments, are discussed.
Incorporating the sustainable development goals in small- to medium-sized enterprises
Authors: Nygaard Sofie , Kokholm Alberte R , Huulgaard Rikke D
Published: October 2022

Multiple international stakeholders emphasise the important role of small- to medium-sized enterprises (SMEs) in achieving the sustainable development goals (SDG). SMEs make up more than 99% of companies in Europe, and holds a potential to promote social and environmental responsibility. However, there is no ‘one size fits all’ when it comes to the incorporation of the SDGs. In this study; we identify five main approaches based on a literature review including (i) rainbow washing, (ii) supporting ‘business as usual’, (iii) adding new initiatives/strategies, (iv) philanthropy and (v) strategic use in core businesses. These approaches are categorised based on their contribution to achieving the SDGs as well as the benefits for the company in question. We performed a case study of six SMEs in Northern Jutland, Denmark, which revealed, that most SMEs work with the SDGs in less proactive and ambitious ways, leaving a gap between the role they have been assigned and their current practices. To investigate this gap further, our case study combined with the literature review has helped identify factors influencing the SMEs choice of approach. These include both negative (uncertainty about the SDGs prospective role, lack of resources and low demand for SDG compliance) and positive (taking responsibility, social license to operate, communication and inspiration) factors. The negative influencing factors are particularly interlinked which is caused by inadequacy in resources, knowledge and qualifications. This indicates that SMEs cannot single-handedly implement the SDGs in a way that enables achievement of the 2030 Agenda, thus external guidance is needed.
ΛCDM halo substructure properties revealed with high-resolution and large-volume cosmological simulations
Authors: Moliné Ángeles , Sánchez-Conde Miguel A , Aguirre-Santaella Alejandra , Ishiyama Tomoaki , Prada Francisco , Cora Sofía A , Croton Darren , Jullo Eric , Metcalf R Benton , Oogi Taira , Ruedas José
Published: October 2022

In this work, we investigate the structural properties, distribution and abundance of ΛCDM dark matter subhaloes using the Phi-4096 and Uchuu suite of N-body cosmological simulations. Thanks to the combination of their large volume, high mass resolution and superb statistics, we are able to quantify – for the first time consistently over more than seven decades in ratio of subhalo-to-host-halo mass – dependencies of subhalo properties on mass, maximum circular velocity, Vmax, host halo mass, and distance to host halo centre. We also dissect the evolution of these dependencies over cosmic time. We provide accurate fits for the subhalo mass and velocity functions, both exhibiting decreasing power-law slopes and with no significant dependence on redshift. We also find subhalo abundance to depend weakly on host halo mass. Subhalo structural properties are codified via a concentration parameter, cV, that does not depend on any pre-defined density profile and relies only on Vmax. We derive the cV−Vmax relation and find an important dependence on distance of the subhalo to the host halo centre. Interestingly, we also find subhaloes of the same mass to be significantly more concentrated when they reside inside more massive hosts. Finally, we investigate the redshift evolution of cV, and provide accurate fits. Our results offer an unprecedented detailed characterization of the subhalo population, consistent over a wide range of subhalo and host halo masses, as well as cosmic times. Thus, we expect our work to be particularly useful for any future research involving dark matter halo substructure.
H i intensity mapping with MeerKAT: power spectrum detection in cross-correlation with WiggleZ galaxies
Authors: Cunnington Steven , Li Yichao , Santos Mario G , Wang Jingying , Carucci Isabella P , Irfan Melis O , Pourtsidou Alkistis , Spinelli Marta , Wolz Laura , Soares Paula S , Blake Chris , Bull Philip , Engelbrecht Brandon , Fonseca José , Grainge Keith , Ma Yin-Zhe
Published: October 2022

We present a detection of correlated clustering between MeerKAT radio intensity maps and galaxies from the WiggleZ Dark Energy Survey. We find a 7.7σ detection of the cross-correlation power spectrum, the amplitude of which is proportional to the product of the ${\rm H}\, {\small I}$ density fraction ($\Omega _{{\rm H}\, {\small I}}$), ${\rm H}\, {\small I}$ bias ($b_{{\rm H}\, {\small I}}$), and the cross-correlation coefficient (r). We therefore obtain the constraint $\Omega _{{\rm H}\, {\small I}}b_{{\rm H}\, {\small I}}r\, {=}\, [0.86\, {\pm }\, 0.10\, ({\rm stat})\, {\pm }\, 0.12\, ({\rm sys})]\, {\times }\, 10^{-3}$, at an effective scale of $k_{\rm eff}\ {\sim }\ 0.13\, h\, \text{Mpc}^{-1}$. The intensity maps were obtained from a pilot survey with the MeerKAT telescope, a 64-dish pathfinder array to the SKA Observatory (SKAO). The data were collected from 10.5 h of observations using MeerKAT’s L-band receivers over six nights covering the 11 h field of WiggleZ, in the frequency range 1015–973 MHz (0.400 $\, {\lt }\, z\, {\lt }\,$ 0.459 in redshift). This detection is the first practical demonstration of the multidish autocorrelation intensity mapping technique for cosmology. This marks an important milestone in the roadmap for the cosmology science case with the full SKAO.
Angular momentum loss rates in Be stars determined by the viscous decretion disc model
Authors: Ghoreyshi M R , Jones C E , Granada A
Published: October 2022

Circumstellar discs around Be stars are formed by the material ejected by the central star. This process removes excess angular momentum from the star as viscosity facilitates the mass and angular momentum transfer within the disc and its growth. The angular momentum loss rates (AMLR) of Be stars is a subject of debate in the literature. Through the modelling of the disc formation and dissipation phases observed from Be stars, their average AMLR can be determined and this is the goal of this work. We use the viscous decretion disc (VDD) model to provide a range of the average AMLR for Be stars and compare these rates with predicted values from the literature. We explore the reasons for discrepancies between the predicted values of average AMLR, using the VDD and Geneva stellar evolution models that were previously reported in literature and find that the largest differences occur when Be stars are rotating below their critical speeds. We show that the time over which the mass reservoir builds up is inversely proportional to the average AMLR. Also, we determine a revised value of the average AMLR for the Galactic Be star ω CMa of $4.7\times 10^{36}\, \mathrm{g\, cm^2\, s^{-2}}$, which is in better agreement with the values expected for a typical B2-type star. Finally, the effect of disc truncation due to the presence of a companion star is investigated and we find that this has a minimal effect on the average AMLR.
Analysis of the ionized interstellar medium and orbital dynamics of PSR J1909-3744 using scintillation arcs
Authors: Askew J , Reardon D J , Shannon R M
Published: October 2022

Long-term studies of binary millisecond pulsars (MSPs) provide precise tests of strong-field gravity, and can be used to measure neutron-star masses. PSR J1909-3744, a binary MSP has been the subject of several pulsar timing analyses. The edge-on orbit enables measurement of its mass using the Shapiro delay; however, there is degeneracy in the sense of the inclination angle, i, and multiple solutions for the longitude of ascending node, Ω. Radio pulsars scintillate due to inhomogeneities in the ionized interstellar medium (IISM). This can result in scintillation arcs in the power spectrum of the dynamic spectrum that can use these to study the interstellar medium and constrain binary pulsar orbits. Here, we study the scintillation of PSR J1909-3744 using observations from the 64-m Parkes Radio Telescope (Murriyang) over ≈13 yr, using techniques to study scintillation in a lower signal-to-noise regime. By monitoring annual and orbital variations of the arc-curvature measurements, we are able to characterize the velocity of the IISM. We find that the statistics of the IISM remained stationary over this time and a slightly anisotropic model (axial ratio ≳1.2) is preferred. We measure the relative distance to a single dominant thin scattering screen at s = 0.49 ± 0.04, or Ds = 590 ± 50 pc, with an angle of anisotropy ζ = 85 ± 6° (East of North) and velocity in the direction of anisotropy VIISM,ζ = 14 ± 10 km s−1. By combining a physical model of the IISM and current pulsar timing results, we also constrain Ω = 225 ± 3° and i = 86.46 ± 0.05°.
The structure and 3D kinematics of vela OB2
Authors: Armstrong Joseph J , Wright Nicholas J , Jeffries R D , Jackson R J , Cantat-Gaudin Tristan
Published: October 2022

The kinematics of stars in OB associations can provide insights into their formation, dynamical evolution, and eventual fate. The low-mass stellar content of OB associations are sufficiently numerous as to provide a detailed sampling of their kinematic properties, however spectroscopy is required to confirm the youth of individual stars and to get 3D kinematics. In this paper, we present and analyse results from a large spectroscopic survey of Vela OB2 conducted using 2dF/HERMES on the AAT. This spectroscopy is used to confirm the youth of candidate young stars and determine radial velocities, which are combined with proper motions and parallaxes from Gaia to measure 3D positions and velocities. We identify multiple separate kinematic groups in the region, for which we measure velocity dispersions and infer their virial states. We measure expansion rates for all these groups and find strong evidence for anisotropic expansion in the Vela OB2 association of at least 11σ significance in all three dimensions, as well as some evidence for expansion in the γ Vel and P Puppis clusters. We trace back the motions of these groups into the past and find that the open cluster NGC 2547 is an interloper in the Vela OB2 region and actually formed >100 pc away from the association. We conclude that Vela OB2 must have formed with considerable spatial and kinematic substructure over a time-scale of ∼10 Myr, with clear temporal substructure within the association, but no clear evidence for an age gradient.
The plasma suppression effect can be ignored in realistic FRB models invoking bunched coherent radio emission
Authors: Qu Yuanhong , Zhang Bing , Kumar Pawan
Published: October 2022

One widely discussed mechanism to produce highly coherent radio emission of fast radio bursts (FRBs) is coherent emission by bunches, either via curvature radiation or inverse Compton scattering (ICS). It has been suggested that the plasma oscillation effect can significantly suppress coherent emission power by bunches. We examine this criticism in this paper. The suppression factor formalism was derived within the context of radio pulsars in which radio waves are in the low-amplitude, linear regime and cannot directly be applied to the large-amplitude, non-linear regime relevant for FRBs. Even if one applies this linear treatment, plasma suppression is not important for two physical reasons. First, for an efficient radiation mechanism, such as ICS, the required plasma density is not high so that a high-density plasma may not exist. Secondly, both bunched coherent mechanisms demand that a large global parallel electric field (E∥) must exist in the emission region in order to continuously inject energy to the bunches to power an FRB. In order to produce typical FRB duration via coherent curvature or ICS radiation, a parallel electric field must be present to balance the acceleration and radiation back reaction. The plasma suppression factor should be modified with the existence of E∥. We show that the correction factor for curvature radiation, fcur, increases with E∥ and becomes 1 when E∥ reaches the radiation-reaction-limited regime. We conclude that the plasma suppression effect can be ignored for realistic FRB emission models invoking bunched coherent radio emission.
A Bayesian Monte Carlo assessment of orbital stability in the late stages of planetary system formation
Authors: Salas Jassyr , Bautista Frank , Chaparro Germán
Published: October 2022

The final orbital configuration of a planetary system is shaped by both its early star–disc environment and late-stage gravitational interactions. Assessing the relative importance of each of these factors is not straightforward due to the observed diversity of planetary systems compounded by observational biases. Our goal is to understand how a planetary system may change when planetesimal accretion and planet migrations stop and secular gravitational effects take over. Our approach starts with a novel classification of planetary systems based on their orbital architecture, validated using Approximate Bayesian Computation methods. We apply this scheme to observed planetary systems and also to ∼400 synthetic systems hosting ∼5000 planets, synthesized from a Monte Carlo planet population model. Our classification scheme robustly yields four system classes according to their planet masses and semimajor axes, for both observed and synthetic systems. We then estimate the orbital distribution density of each of the synthetic systems before and after dynamically evolving for 0.1–1 Myr using a gravitational + collisional N-body code. Using the Kullback–Leibler divergence to statistically measure orbital configuration changes, we find that ≲10 per cent of synthetic planetary systems experience such changes. We also find that this fraction belongs to a class of systems for which their centre of mass is very close to their host star. Although changes in the orbital configuration of planetary systems may not be very common, they are more likely to happen in systems with close-in, massive planets, with F- and G-type host-stars and stellar metallicities [Fe/H] >0.2.
Dust formation in the outflows of catastrophically evaporating planets
Authors: Booth Richard A , Owen James E , Schulik Matthäus
Published: October 2022

Ultrashort period planets offer a window into the poorly understood interior composition of exoplanets through material evaporated from their rocky interiors. Among these objects are a class of disintegrating planets, observed when their dusty tails transit in front of their host stars. These dusty tails are thought to originate from dust condensation in thermally driven winds emanating from the sublimating surfaces of these planets. Existing models of these winds have been unable to explain their highly variable nature and have not explicitly modelled how dust forms in the wind. Here, we present new radiation-hydrodynamic simulations of the winds from these planets, including a minimal model for the formation and destruction of dust, assuming that nucleation can readily take place. We find that dust forms readily in the winds, a consequence of large dust grains obtaining lower temperatures than the planet’s surface. As hyphothesized previously, we find that the coupling of the planet’s surface temperature to the outflow properties via the dust’s opacity can drive time-variable flows when dust condensation is sufficiently fast. In agreement with previous work, our models suggest that these dusty tails are a signature of catastrophically evaporating planets that are close to the end of their lives. Finally, we discuss the implications of our results for the dust’s composition. More detailed hydrodynamic models that self-consistently compute the nucleation and composition of the dust and gas are warranted in order to use these models to study the planet’s interior composition.
Radio observations of the tidal disruption event AT2020opy: a luminous non-relativistic outflow encountering a dense circumnuclear medium
Authors: Goodwin A J , Miller-Jones J C A , van Velzen S , Bietenholz M , Greenland J , Cenko B , Gezari S , Horesh A , Sivakoff G R , Yan L , Yu W , Zhang X
Published: October 2022

Tidal disruption events (TDEs) occur when a star passes too close to a supermassive black hole and is destroyed by tidal gravitational forces. Radio observations of TDEs trace synchrotron emission from outflowing material that may be ejected from the inner regions of the accretion flow around the supermassive black hole or by the tidal debris stream. Radio detections of TDEs are rare, but provide crucial information about the launching of jets and outflows from supermassive black holes and the circumnuclear environment in galaxies. Here, we present the radio detection of the TDE AT2020opy, including three epochs of radio observations taken with the Karl G. Jansky Very Large Array, MeerKAT, and upgraded Giant Metrewave Radio telescope. AT2020opy is the most distant thermal TDE with radio emission reported to date, and from modelling the evolving synchrotron spectra we deduce that the host galaxy has a more dense circumnuclear medium than other thermal TDEs detected in the radio band. Based on an equipartition analysis of the synchrotron spectral properties of the event, we conclude that the radio-emitting outflow was likely launched approximately at the time of, or just after, the initial optical flare. We find no evidence for relativistic motion of the outflow. The high luminosity of this event supports that a dense circumnuclear medium of the host galaxy produces brighter radio emission that rises to a peak more quickly than in galaxies with lower central densities.
A Sun-like star orbiting a black hole
Authors: El-Badry Kareem , Rix Hans-Walter , Quataert Eliot , Howard Andrew W , Isaacson Howard , Fuller Jim , Hawkins Keith , Breivik Katelyn , Wong Kaze W K , Rodriguez Antonio C , Conroy Charlie , Shahaf Sahar , Mazeh Tsevi , Arenou Frédéric , Burdge Kevin B , Bashi Dolev , Faigler Simchon , Weisz Daniel R , Seeburger Rhys , Almada Monter Silvia , Wojno Jennifer
Published: October 2022

We report discovery of a bright, nearby ($G = 13.8;\, \, d = 480\, \rm pc$) Sun-like star orbiting a dark object. We identified the system as a black hole candidate via its astrometric orbital solution from the Gaia mission. Radial velocities validated and refined the Gaia solution, and spectroscopy ruled out significant light contributions from another star. Joint modelling of radial velocities and astrometry constrains the companion mass of $M_2 = 9.62\pm 0.18\, \mathrm{M}_{\odot }$. The spectroscopic orbit alone sets a minimum companion mass of $M_2\gt 5\, \mathrm{M}_{\odot }$; if the companion were a $5\, \mathrm{M}_{\odot }$ star, it would be 500 times more luminous than the entire system. These constraints are insensitive to the mass of the luminous star, which appears as a slowly rotating G dwarf ($T_{\rm eff}=5850\, \rm K$, log g = 4.5, $M=0.93\, \mathrm{M}_{\odot }$), with near-solar metallicity ($\rm [Fe/H] = -0.2$) and an unremarkable abundance pattern. We find no plausible astrophysical scenario that can explain the orbit and does not involve a black hole. The orbital period, Porb = 185.6 d, is longer than that of any known stellar-mass black hole binary. The system’s modest eccentricity (e = 0.45), high metallicity, and thin-disc Galactic orbit suggest that it was born in the Milky Way disc with at most a weak natal kick. How the system formed is uncertain. Common envelope evolution can only produce the system’s wide orbit under extreme and likely unphysical assumptions. Formation models involving triples or dynamical assembly in an open cluster may be more promising. This is the nearest known black hole by a factor of 3, and its discovery suggests the existence of a sizable population of dormant black holes in binaries. Future Gaia releases will likely facilitate the discovery of dozens more.
Three-dimensional propagation of kink wave trains in solar coronal slabs
Authors: Li Bo , Guo Mingzhe , Yu Hui , Chen Shao-Xia , Shi Mijie
Published: October 2022

Impulsively excited wave trains are of considerable interest in solar coronal seismology. To our knowledge, however, it remains to examine the three-dimensional (3D) dispersive propagation of impulsive kink waves in straight, field-aligned, symmetric, low-beta, slab equilibria that are structured only in one transverse direction. We offer a study here, starting with an analysis of linear oblique kink modes from an eigenvalue problem perspective. Two features are numerically found for continuous and step structuring alike, one being that the group and phase velocities may lie on opposite sides of the equilibrium magnetic field ($\boldsymbol {B}_0$), and the other being that the group trajectories extend only to a limited angle from $\boldsymbol {B}_0$. We justify these features by making analytical progress for the step structuring. More importantly, we demonstrate by a 3D time-dependent simulation that these features show up in the intricate interference patterns of kink wave trains that arise from a localized initial perturbation. In a plane perpendicular to the direction of inhomogeneity, the large-time slab-guided patterns are confined to a narrow sector about $\boldsymbol {B}_0$, with some wavefronts propagating toward $\boldsymbol {B}_0$. We conclude that the phase and group diagrams lay the necessary framework for understanding the complicated time-dependent behaviour of impulsive waves.
A case of giant cell arteritis complicated by polymyalgia rheumatica with scalp necrosis and refractory jaw claudication
Authors: Kosaka Shumpei , Nawata Masao , Yamazumi Kenji , Nawata Aya , Nakamura Katsumi , Saito Kazuyoshi , Tanaka Yoshiya
Published: October 2022

Scalp necrosis is a rare complication of giant cell arteritis (GCA); however, it is a predictor of severe disease. In this case study, a patient presented with GCA complicated by polymyalgia rheumatica with scalp necrosis. An 86-year-old woman was admitted to the hospital for pulsating headache, scalp pain, jaw claudication, and generalised pain. Bilateral temporal arteries were found to be distended and pulseless, and scalp necrosis was observed in the parietal region. Simultaneous high-resolution contrast-enhanced magnetic resonance imaging (MRI) sequences of the head, shoulder, and hip showed staining around the bilateral shallow temporal arteries, shoulder, and hip joints, which was confirmed as GCA with polymyalgia rheumatica using other examination findings. After treatment with early induction remission therapy, scalp necrosis healed, but jaw claudication persisted. Six months after the start of treatment, scalp necrosis was cured to full hair growth. Despite remission induction therapy combined with tocilizumab, the patient had persistent jaw claudication for several months. At that time, a high-resolution contrast-enhanced MRI re-examination was useful in assessing disease activity. GCA with scalp necrosis may cause prolonged jaw claudication reflecting the progression of ischaemic lesions, whereas the disease activity can be accurately assessed by combining MRI studies.
Perceived Health and Capacity to Cope With Stress in Recent Ex-smokers: Impact of Vaping Versus Quitting All Nicotine
Authors: Le Grande Michael , Balmford James , Borland Ron , McNeill Ann
Published: October 2022

Introduction

Little is known about the continued use of nicotine following smoking cessation on perceived well-being in comparison to complete cessation of nicotine use.

Aims and Methods

To explore aspects of perceived well-being and coping among recent ex-smokers as a function of vaping status. Ever-daily smokers in the International Tobacco Control 4 country smoking and vaping surveys in 2016 (w1 N = 883) and 2018 (w2 N = 1088). Cross-sectional associations and longitudinal samples for those who quit between waves and those who quit at w1 and maintained abstinence to w2. Main outcome measures were: Past 30 days of depression symptoms, perceived stress, stress management since quitting, and change in perceived day-to-day health.

Results

In the cross-sectional analyses vapers were more likely to report both improved stress management (aOR = 1.71, 95% CI 1.23–2.36) and perceived day-to-day health (aOR = 1.65, 95% CI 1.26–2.16) than nicotine abstainers. In the longitudinal analyses, smokers who switched to vaping between waves (n = 372) were more likely to report depression symptoms at w2 (aOR = 2.00, 95% CI 1.09–3.65) but reported improved perceived health (aOR = 1.92, 95% CI 1.16–3.20). For the past daily smokers who remained quit between waves (n = 382), vapers were more likely to report improved stress management relative to abstainers (RRR = 5.05. 95% CI 1.19–21.40). There were no other significant differences between vapers and nicotine abstainers.

Conclusions

There is little evidence to support the view that perceptions of well-being deteriorate in vapers compared to complete nicotine abstainers in the immediate years after smoking cessation.

Implications

This study could find no conclusive evidence that the continued use of nicotine via e-cigarettes was detrimental to health compared to completely stopping nicotine intake altogether. Our results would suggest that continuing to use nicotine may even result in some benefits in the short term such as improved stress management, however further longitudinal studies are required to examine if these effects are restricted to the early post-quitting phase and whether other positive or negative effects on psychosocial health emerge in the future.