X-Ray Luminous Supernovae: Threats to Terrestrial Biospheres

The spectacular outbursts of energy associated with supernovae (SNe) have long motivated research into their potentially hazardous effects on Earth and analogous environments. Much of this research has focused primarily on the atmospheric damage associated with the prompt arrival of ionizing photons within days or months of the initial outburst, and the high-energy cosmic rays that arrive thousands of years after the explosion. In this study, we turn the focus to persistent X-ray emission, arising in certain SNe that have interactions with a dense circumstellar medium, and observed months and/or years after the initial outburst. The sustained high X-ray luminosity leads to large doses of ionizing radiation out to formidable distances. We provide an assessment of the threat posed by these X-ray luminous SNe by analyzing the collective X-ray observations from Chandra, Swift-XRT, XMM-Newton, NuSTAR, and others. We find that this threat is particularly acute for SNe showing evidence of strong circumstellar interaction, such as Type IIn explosions, which have significantly larger ranges of influence than previously expected, and lethal consequences up to $\sim$ 50 pc away. Furthermore, X-ray bright SNe could pose a substantial and distinct threat to terrestrial biospheres, and tighten the Galactic habitable zone. We urge follow-up X-ray observations of interacting SNe for months and years after the explosion to shed light on the physical nature of the emission and its full time evolution, and to clarify the danger that these events pose for life in our Galaxy and other star-forming regions.Comment: 24 pages, 6 figures. Now includes a more detailed analysis of X-ray effectiveness for ozone destruction; conclusions unchanged. Matches version to appear in Ap

Sigurðar saga fóts (The Saga of Sigurðr Foot): A Translation

This is the first English translation of the short Icelandic romance Sigurðar saga fóts, with an introduction presenting the evidence for its dating and immediate literary context. Like most Icelandic romances, Sigurðar saga is a bridal-quest story; the support of a foster-brother is key to the hero winning the bride; and the foster-brothers start out as opponents before recognising their mutual excellence and swearing foster-brotherhood. Uniquely, however, the men who become foster-brothers begin by competing for the same bride (Signý): the eponymous Sigurðr fótr wins Signý only because Ásmundr gives her to him in exchange for foster-brotherhood. Ásmundr’s decision can be read as demonstrating with unusual starkness the superior importance in much Icelandic romance of homosocial relationships over heterosexual ones, giving the saga a certain paradigmatic status. Translating the saga in an open-access forum and reconstructing its literary context will, we hope, encourage further analyses

Sigurðar saga fóts (The Saga of Sigurðr Foot): A Translation

This is the first English translation of the short Icelandic romance Sigurðar saga fóts, with an introduction presenting the evidence for its dating and immediate literary context. Like most Icelandic romances, Sigurðar saga is a bridal-quest story; the support of a foster-brother is key to the hero winning the bride; and the foster-brothers start out as opponents before recognising their mutual excellence and swearing foster-brotherhood. Uniquely, however, the men who become foster-brothers begin by competing for the same bride (Signý): the eponymous Sigurðr fótr wins Signý only because Ásmundr gives her to him in exchange for foster-brotherhood. Ásmundr’s decision can be read as demonstrating with unusual starkness the superior importance in much Icelandic romance of homosocial relationships over heterosexual ones, giving the saga a certain paradigmatic status. Translating the saga in an open-access forum and reconstructing its literary context will, we hope, encourage further analyses

Pulse consumption improves indices of glycemic control in adults with and without type 2 diabetes: a systematic review and meta-analysis of acute and long-term randomized controlled trials.

Funder: University of LeedsPURPOSE: Findings from randomized controlled trials (RCTs) evaluating the effect of pulse intake on glycemic control are inconsistent and conclusive evidence is lacking. The aim of this study was to systematically review the impact of pulse consumption on post-prandial and long-term glycemic control in adults with and without type 2 diabetes (T2D). METHODS: Databases were searched for RCTs, reporting outcomes of post-prandial and long-term interventions with different pulse types on parameters of glycemic control in normoglycemic and T2D adults. Effect size (ES) was calculated using random effect model and meta-regression was conducted to assess the impact of various moderator variables such as pulse type, form, dose, and study duration on ES. RESULTS: From 3334 RCTs identified, 65 studies were eligible for inclusion involving 2102 individuals. In acute RCTs, pulse intake significantly reduced peak post-prandial glucose concentration in participants with T2D (ES  - 2.90; 95%CI  - 4.60,  - 1.21; p ≤ 0.001; I2 = 93%) and without T2D (ES  - 1.38; 95%CI  - 1.78,  - 0.99; p ≤ 0.001; I2 = 86%). Incorporating pulse consumption into long-term eating patterns significantly attenuated fasting glucose in normoglycemic adults (ES  - 0.06; 95%CI  - 0.12, 0.00; p ≤ 0.05; I2 = 30%). Whereas, in T2D participants, pulse intake significantly lowered fasting glucose (ES  - 0.54; 95%CI  - 0.83,  - 0.24; p ≤ 0.001; I2 = 78%), glycated hemoglobin A1c (HbA1c) (ES  - 0.17; 95%CI  - 0.33, 0.00; p ≤ 0.05; I2 = 78) and homeostatic model assessment of insulin resistance (HOMA-IR) (ES  - 0.47; 95%CI  - 1.25,  - 0.31; p ≤ 0.05; I2 = 79%). CONCLUSION: Pulse consumption significantly reduced acute post-prandial glucose concentration > 1 mmol/L in normoglycemic adults and > 2.5 mmol/L in those with T2D, and improved a range of long-term glycemic control parameters in adults with and without T2D. PROSPERO REGISTRY NUMBER: (CRD42019162322)

Shared Antigen-specific CD8⁺ T cell Responses Against the SARS-COV-2 Spike Protein in HLA A*02:01 COVID-19 Participants

We report here on antigens from the SARS-CoV-2 virus spike protein, that when presented by Class I MHC, can lead to cytotoxic CD8⁺ T cell anti-viral responses in COVID-19 patients. We present a method in which the SARS-CoV-2 spike protein is converted into a library of peptide antigen-Major Histocompatibility Complexes (pMHCs) as single chain trimers that contain the peptide antigen, the MHC HLA allele, and the β-2 microglobulin sub-unit. That library is used to detect the evolution of virus-specific T cell populations from two COVID-19 patients, at two time points over the course of infection. Both patients exhibit similar virus-specific T cell populations, but very different time-trajectories of those populations. These results can be used to track those virus-specific T cell populations over the course of an infection, thus providing deep insight into the variations in immune system trajectories observed in different COVID-19 patients

The prevalence and long-term health effects of Long Covid among hospitalised and non-hospitalised populations: A systematic review and meta-analysis

BACKGROUND: The aim of this study was to systematically synthesise the global evidence on the prevalence of persistent symptoms in a general post COVID-19 population. METHODS: A systematic literature search was conducted using multiple electronic databases (MEDLINE and The Cochrane Library, Scopus, CINAHL, and medRxiv) until January 2022. Studies with at least 100 people with confirmed or self-reported COVID-19 symptoms at ≥28 days following infection onset were included. Patient-reported outcome measures and clinical investigations were both assessed. Results were analysed descriptively, and meta-analyses were conducted to derive prevalence estimates. This study was pre-registered (PROSPERO-ID: CRD42021238247). FINDINGS: 194 studies totalling 735,006 participants were included, with five studies conducted in those <18 years of age. Most studies were conducted in Europe (n = 106) or Asia (n = 49), and the time to follow-up ranged from ≥28 days to 387 days. 122 studies reported data on hospitalised patients, 18 on non-hospitalised, and 54 on hospitalised and non-hospitalised combined (mixed). On average, at least 45% of COVID-19 survivors, regardless of hospitalisation status, went on to experience at least one unresolved symptom (mean follow-up 126 days). Fatigue was frequently reported across hospitalised (28.4%; 95% CI 24.7%-32.5%), non-hospitalised (34.8%; 95% CI 17.6%-57.2%), and mixed (25.2%; 95% CI 17.7%-34.6%) cohorts. Amongst the hospitalised cohort, abnormal CT patterns/x-rays were frequently reported (45.3%; 95% CI 35.3%-55.7%), alongside ground glass opacification (41.1%; 95% CI 25.7%-58.5%), and impaired diffusion capacity for carbon monoxide (31.7%; 95% CI 25.8%-3.2%). INTERPRETATION: Our work shows that 45% of COVID-19 survivors, regardless of hospitalisation status, were experiencing a range of unresolved symptoms at ∼ 4 months. Current understanding is limited by heterogeneous study design, follow-up durations, and measurement methods. Definition of subtypes of Long Covid is unclear, subsequently hampering effective treatment/management strategies. FUNDING: No funding

The 'causes' of teenage pregnancy: review of South African research - Part 2

This article forms the second of a two-part series in which South African research on teenage pregnancy is reviewed. Part 1 of the series dealt with the consequences of teenage pregnancy; this paper reviews the 'causes' thereof. International literature is incorporated in the discussion by way of comparison. Contributory factors which have been investigated by South African researchers include: reproductive ignorance; the earlier occurrence of menarche; risktaking behaviour; psychological problems; peer influence; co-ercive sexual relations; dysfunctional family patterns; poor health services; socio-economic status; the breakdown of cultural traditions; and the cultural value placed on children. Preston-Whyte and colleagues present a revisionist argument, stating that early pregnancy may represent a rational life choice for certain adolescent women. The article is concluded with comments on methodological problems encountered in the South African research, and a discussion on the implications in terms of policy formulation

From Interactions to Institutions: Microprocesses of Framing and Mechanisms for the Structuring of Institutional Fields

Despite the centrality of meaning to institutionalization, little attention has been paid to how meanings evolve and amplify to become institutionalized cultural conventions. We develop an interactional framing perspective to explain the microprocesses and mechanisms by which this occurs. We identify three amplification processes and three ways frames stack up or laminate that become the building blocks for diffusion and institutionalization of meanings within organizations and fields. Although we focus on “bottom-up” dynamics, we argue that framing occurs in a politicized social context and is inherently bidirectional, in line with structuration, because microlevel interactions instantiate macrostructures. We consider how our approach complements other theories of meaning making, its utility for informing related theoretical streams, and its implications for organizing at the meso and macro levels