Magnetic Field Generation in Stars

Enormous progress has been made on observing stellar magnetism in stars from the main sequence through to compact objects. Recent data have thrown into sharper relief the vexed question of the origin of stellar magnetic fields, which remains one of the main unanswered questions in astrophysics. In this chapter we review recent work in this area of research. In particular, we look at the fossil field hypothesis which links magnetism in compact stars to magnetism in main sequence and pre-main sequence stars and we consider why its feasibility has now been questioned particularly in the context of highly magnetic white dwarfs. We also review the fossil versus dynamo debate in the context of neutron stars and the roles played by key physical processes such as buoyancy, helicity, and superfluid turbulence,in the generation and stability of neutron star fields. Independent information on the internal magnetic field of neutron stars will come from future gravitational wave detections. Thus we maybe at the dawn of a new era of exciting discoveries in compact star magnetism driven by the opening of a new, non-electromagnetic observational window. We also review recent advances in the theory and computation of magnetohydrodynamic turbulence as it applies to stellar magnetism and dynamo theory. These advances offer insight into the action of stellar dynamos as well as processes whichcontrol the diffusive magnetic flux transport in stars.Comment: 41 pages, 7 figures. Invited review chapter on on magnetic field generation in stars to appear in Space Science Reviews, Springe

Evolution of the use of corticosteroids for the treatment of hospitalised COVID-19 patients in Spain between March and November 2020: SEMI-COVID national registry

Objectives: Since the results of the RECOVERY trial, WHO recommendations about the use of corticosteroids (CTs) in COVID-19 have changed. The aim of the study is to analyse the evolutive use of CTs in Spain during the pandemic to assess the potential influence of new recommendations. Material and methods: A retrospective, descriptive, and observational study was conducted on adults hospitalised due to COVID-19 in Spain who were included in the SEMI-COVID- 19 Registry from March to November 2020. Results: CTs were used in 6053 (36.21%) of the included patients. The patients were older (mean (SD)) (69.6 (14.6) vs. 66.0 (16.8) years; p < 0.001), with hypertension (57.0% vs. 47.7%; p < 0.001), obesity (26.4% vs. 19.3%; p < 0.0001), and multimorbidity prevalence (20.6% vs. 16.1%; p < 0.001). These patients had higher values (mean (95% CI)) of C-reactive protein (CRP) (86 (32.7-160) vs. 49.3 (16-109) mg/dL; p < 0.001), ferritin (791 (393-1534) vs. 470 (236- 996) µg/dL; p < 0.001), D dimer (750 (430-1400) vs. 617 (345-1180) µg/dL; p < 0.001), and lower Sp02/Fi02 (266 (91.1) vs. 301 (101); p < 0.001). Since June 2020, there was an increment in the use of CTs (March vs. September; p < 0.001). Overall, 20% did not receive steroids, and 40% received less than 200 mg accumulated prednisone equivalent dose (APED). Severe patients are treated with higher doses. The mortality benefit was observed in patients with oxygen saturation </=90%. Conclusions: Patients with greater comorbidity, severity, and inflammatory markers were those treated with CTs. In severe patients, there is a trend towards the use of higher doses. The mortality benefit was observed in patients with oxygen saturation </=90%

Multi-ancestry transcriptome-wide association analyses yield insights into tobacco use biology and drug repurposing

Most transcriptome-wide association studies (TWASs) so far focus on European ancestry and lack diversity. To overcome this limitation, we aggregated genome-wide association study (GWAS) summary statistics, whole-genome sequences and expression quantitative trait locus (eQTL) data from diverse ancestries. We developed a new approach, TESLA (multi-ancestry integrative study using an optimal linear combination of association statistics), to integrate an eQTL dataset with a multi-ancestry GWAS. By exploiting shared phenotypic effects between ancestries and accommodating potential effect heterogeneities, TESLA improves power over other TWAS methods. When applied to tobacco use phenotypes, TESLA identified 273 new genes, up to 55% more compared with alternative TWAS methods. These hits and subsequent fine mapping using TESLA point to target genes with biological relevance. In silico drug-repurposing analyses highlight several drugs with known efficacy, including dextromethorphan and galantamine, and new drugs such as muscle relaxants that may be repurposed for treating nicotine addiction

Fusarium: more than a node or a foot-shaped basal cell

Recent publications have argued that there are potentially serious consequences for researchers in recognising distinct genera in the terminal fusarioid clade of the family Nectriaceae. Thus, an alternate hypothesis, namely a very broad concept of the genus Fusarium was proposed. In doing so, however, a significant body of data that supports distinct genera in Nectriaceae based on morphology, biology, and phylogeny is disregarded. A DNA phylogeny based on 19 orthologous protein-coding genes was presented to support a very broad concept of Fusarium at the F1 node in Nectriaceae. Here, we demonstrate that re-analyses of this dataset show that all 19 genes support the F3 node that represents Fusarium sensu stricto as defined by F. sambucinum (sexual morph synonym Gibberella pulicaris). The backbone of the phylogeny is resolved by the concatenated alignment, but only six of the 19 genes fully support the F1 node, representing the broad circumscription of Fusarium. Furthermore, a re-analysis of the concatenated dataset revealed alternate topologies in different phylogenetic algorithms, highlighting the deep divergence and unresolved placement of various Nectriaceae lineages proposed as members of Fusarium. Species of Fusarium s. str. are characterised by Gibberella sexual morphs, asexual morphs with thin- or thick-walled macroconidia that have variously shaped apical and basal cells, and trichothecene mycotoxin production, which separates them from other fusarioid genera. Here we show that the Wollenweber concept of Fusarium presently accounts for 20 segregate genera with clear-cut synapomorphic traits, and that fusarioid macroconidia represent a character that has been gained or lost multiple times throughout Nectriaceae. Thus, the very broad circumscription of Fusarium is blurry and without apparent synapomorphies, and does not include all genera with fusarium-like macroconidia, which are spread throughout Nectriaceae (e.g., Cosmosporella, Macroconia, Microcera). In this study four new genera are introduced, along with 18 new species and 16 new combinations. These names convey information about relationships, morphology, and ecological preference that would otherwise be lost in a broader definition of Fusarium. To assist users to correctly identify fusarioid genera and species, we introduce a new online identification database, Fusarioid-ID, accessible at www.fusarium.org. The database comprises partial sequences from multiple genes commonly used to identify fusarioid taxa (act1, CaM, his3, rpb1, rpb2, tef1, tub2, ITS, and LSU). In this paper, we also present a nomenclator of names that have been introduced in Fusarium up to January 2021 as well as their current status, types, and diagnostic DNA barcode data. In this study, researchers from 46 countries, representing taxonomists, plant pathologists, medical mycologists, quarantine officials, regulatory agencies, and students, strongly support the application and use of a more precisely delimited Fusarium (= Gibberella) concept to accommodate taxa from the robust monophyletic node F3 on the basis of a well-defined and unique combination of morphological and biochemical features. This F3 node includes, among others, species of the F. fujikuroi, F. incarnatum-equiseti, F. oxysporum, and F. sambucinum species complexes, but not species of Bisifusarium [F. dimerum species complex (SC)], Cyanonectria (F. buxicola SC), Geejayessia (F. staphyleae SC), Neocosmospora (F. solani SC) or Rectifusarium (F. ventricosum SC). The present study represents the first step to generating a new online monograph of Fusarium and allied fusarioid genera (www.fusarium.org)

Genetic determinants of telomere length from 109,122 ancestrally diverse whole-genome sequences in TOPMed

Genetic studies on telomere length are important for understanding age-related diseases. Prior GWASs for leukocyte TL have been limited to European and Asian populations. Here, we report the first sequencing-based association study for TL across ancestrally diverse individuals (European, African, Asian, and Hispanic/Latino) from the NHLBI Trans-Omics for Precision Medicine (TOPMed) program. We used whole-genome sequencing (WGS) of whole blood for variant genotype calling and the bioinformatic estimation of telomere length in n = 109,122 individuals. We identified 59 sentinel variants (p &lt; 5 × 10−9) in 36 loci associated with telomere length, including 20 newly associated loci (13 were replicated in external datasets). There was little evidence of effect size heterogeneity across populations. Fine-mapping at OBFC1 indicated that the independent signals colocalized with cell-type-specific eQTLs for OBFC1 (STN1). Using a multi-variant gene-based approach, we identified two genes newly implicated in telomere length, DCLRE1B (SNM1B) and PARN. In PheWAS, we demonstrated that our TL polygenic trait scores (PTSs) were associated with an increased risk of cancer-related phenotypes

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

Introduction: The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures. Methods: In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025. Findings: Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2–6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p5mg/L, OR 3·55 [1·23–11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation. Interpretation: After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification. Funding: UK Research and Innovation and National Institute for Health Research

Necrotising enterocolitis: Case series, of General Hospital of Mexico Dr. Eduardo Liceaga

Background: Necrotising enterocolitis (NEC) is an acute inflammatory condition of the colon involving a wide range of diseases with one end result: necrosis. This disease entity is very common in preterm infants, since 5–10% of premature babies weighing less than 1.5 kg are believed to suffer from it, and it has a mortality rate of around 50% of cases. Objective: To describe the clinical and pathological characteristics of 24 patients with an established diagnosis of NEC and to identify their characteristics in terms of demographics, concomitant diagnoses and treatment response in order to provide preliminary data for designing prospective studies and future medical interventions. Materials and methods: Information for 24 autopsied neonates who died of complications of NEC between 1993 and 2013 was compiled and analysed retrospectively. Results: Of all 24 cases diagnosed with necrotising enterocolitis, only 15 were diagnosed clinically; all others (9 cases) were diagnosed post mortem. During autopsy, the most common finding was bleeding in different gastrointestinal segments (n = 13 patients [53.9%]), followed by necrosis (n = 9 [37.5%]) and perforation (n = 10 [41.6%]). Four of the eight cases in which the Bell's clinical stage was reported could not be correlated with the pathological findings. Conclusions: As NEC is a disease with a high mortality rate, it is necessary to increase our knowledge of the demographic and clinical characteristics of patients with the disease to make a diagnosis that enables the patient to have early access to efficient therapeutic interventions. Our results demonstrate broad difficulty in the clinical diagnosis of this condition, as well as a weak relationship between the clinical stage reported and the pathological characteristics found during autopsy. The significance of this case series lies in its demonstration of the lack of accurate knowledge and identification of the clinical and demographic characteristics of patients with necrotising enterocolitis and the need for greater understanding of the pathophysiological foundations of this disease. Resumen: Antecedentes: La enterocolitis necrotizante (ECN) es un padecimiento agudo inflamatorio del colon que involucra un amplio espectro de enfermedades con un resultado final, la necrosis. Esta entidad nosológica es muy frecuente en neonatos pretérmino; ya que se considera que del 5 al 10% de los prematuros que pesan menos de 1.5 kg la padecen, teniendo una mortalidad cercana al 50% de los casos. Objetivo: Describir las características clínicas y anatomopatológicas de 24 pacientes con diagnóstico de ECN establecido, e identificar sus características demográficas, de diagnósticos concomitantes y respuesta a tratamiento con el fin de proveer datos preliminares para diseño de estudios prospectivos e intervenciones médicas futuras. Materiales y métodos: Se recopiló y analizó retrospectivamente la información de 24 casos de autopsia de neonatos que murieron a causa de complicaciones de ECN en el periodo de 1993 a 2013. Resultados: Del total de 24 casos con diagnóstico de enterocolitis necrotizante en solo 15 el diagnóstico fue establecido clínicamente, ya que en el resto (9 casos) el diagnóstico fue postmortem. Durante la autopsia el hallazgo más frecuente fue la hemorragia en diferentes segmentos gastrointestinales n = 13 pacientes (53.9%), seguido por la necrosis n = 9 (37.5%) y la perforación n = 10 (41.6%). En cuatro de los ocho pacientes en los que se reportó el estadio clínico de Bell no pudo correlacionarse con los hallazgos anatomopatológicos. Conclusiones: Al ser una enfermedad con una alta tasa de mortalidad es necesario aumentar nuestro conocimiento acerca de las características demográficas y clínicas de los pacientes con ECN, para poder establecer un diagnóstico que permita al paciente acceder a intervenciones terapéuticas eficientes de manera temprana. Nuestros resultados demuestran amplia dificultad en el diagnóstico clínico de este padecimiento, así como poca relación entre el estadio clínico reportado y las características anatomopatológicas encontradas durante los estudios de autopsia. La importancia de esta serie de casos radica en demostrar la falta de conocimiento e identificación certera de las características clínicas y demográficas de los pacientes con enterocolitis necrotizante y la necesidad de una mayor comprensión de las bases fisiopatológicas de esta enfermedad. Keywords: Necrotising enterocolitis, Prematurity, Neonate, Necrosis, Sepsis, Palabras clave: Enterocolitis necrotizante, Prematurez, Neonato, Necrosis, Sepsi

Clonal building, simple growth rules and phylloclimate as key steps to develop functional-structural seagrass models

The repetitive clonal growth of the seagrasses Zostera noltii Hornem. and Cymodocea nodosa Aschers at the module level was used to implement a deterministic, individual-based, numerical model using the simplest growth rules. Inter- and intraspecific variability in plant morphology and meadow attributes was simulated, and the results yielded by the model were compared with an existing large data set recorded for both species. The model outputs showed that intra- and interspecific morphological variability can be accurately described (r = 0.99, p < 0.0001, n = 19) by a restricted number of parameters (plastochrone interval [PI] and elongation rates for rhizome [RER] and leaf [LER], which are species-specific parameters). Interspecific differences in meadow properties were recorded; however, simulated values were double those observed. This result was mainly attributable to a lack of density-dependence phenomena in the model assumptions, revealing the importance of such phenomena in structuring seagrass populations. In general, species with high PIs displayed longer modules (leaves and internodes) and lower shoot densities, whereas species with lower PI values developed shorter modules and crowded stands. This result corresponds with the relationship indicated by the self-thinning law and by previous studies. The model also showed that plant morphology arises as an emergent property of a simple set of growth rules acting at the module level, and that plant dynamic parameters can be tuned by seagrasses in response to their local environmental conditions. Thus, the whole-plant response to the environment can be determined by the sum of all the modular responses. This model, together with a better knowledge of the regulation of plant dynamic parameters by control variables (light, temperature, nutrients, etc.), provides a conceptual framework that allows the incorporation of module, plant morphology and meadow properties into functional–structural seagrass models, in which feedbacks among plant morphology, plant development and phylloclimate (i.e. the physical environment actually perceived by each individual organ or plant population) can be included. [KEYWORDS: Cymodocea nodosa · Zostera noltii ; Clonal growth ; Light reduction ; Nutrient enrichment ; Plant dynamic parameters ; Plastochrone interval ; Rhizome-elongation rate ; Leaf-elongation rate]