Understanding the neutrino mass constraints achievable by combining CMB lensing and spectroscopic galaxy surveys

We perform a thorough examination of the neutrino mass ($M_\nu$) constraints achievable by combining future spectroscopic galaxy surveys with cosmic microwave background (CMB) experiments, focusing on the contribution of CMB lensing. CMB lensing can help by breaking the $M_\nu$-curvature degeneracy when combined with baryon acoustic oscillation (BAO)-only measurements, but we demonstrate this combination wastes a great deal of constraining power, as the broadband shape of the power spectrum contributes significantly to constraints. We also expand on previous work to demonstrate how cosmology-independent constraints on $M_\nu$ can be extracted by combining measurements of the scale-dependence in the power spectrum caused by neutrino free-streaming with the full power of future CMB surveys. These free-streaming constraints are independent of the optical depth to the CMB ($\tau$) and give stronger constraints alone on $M_\nu$ than are given by the combination of BAOs and CMB lensing. Finally, we demonstrate that the effect of including the galaxy-CMB lensing cross power spectrum is negligible.Comment: For submission to JCA

Understanding neutrino mass constraints from galaxy clustering and CMB lensing

This thesis is the result of a long endeavour to bring new perspectives and insights to the challenge of extracting strong and robust neutrino mass constraints from current and future cosmological measurements. Although cosmology provides the strongest constraints on the neutrino mass today and will likely continue to into the foreseeable future, ensuring that these constraints are robust enough to also convince scientists outside of the cosmology community must be a crucial priority. The vast majority of current or forecasted cosmological neutrino mass constraints in the literature assume the concordance flat Lambda-CDM model when extracting their results. Despite its many successes, the Lambda-CDM model is not without challenges, both theoretical and observational. It is important that any changes that are made to this model in future do not significantly alter our neutrino mass measurements. The goal of our work has been to understand the significance of this cosmological assumption, to understand possible degeneracies between the neutrino mass and other cosmological parameters, and to examine how much we can really claim about the capacity of cosmological measurements to measure the neutrino mass. We take a semi-analytical approach, using the Fisher matrix formalism. In Chapter 2, we thoroughly deconstruct the constraints on the neutrino mass available from future galaxy redshift surveys. Galaxy clustering measurements are sensitive to massive neutrinos in many ways. We provide isolated constraints from expansion rate measurements provided by baryon-acoustic oscillations (BAOs) and the Alcock-Paczy\'nski test. We also demonstrate the constraining power of redshift-space distortions (RSD). We develop a new method of isolating the characteristic scale-dependent suppression in the power spectrum as a probe of the neutrino mass, and show that the constraints it provides are both cosmology-independent and relatively powerful. We show that all of the other individual probes of the neutrino mass and the combined constraints are strongly cosmology-dependent. In addition, although it was already known that there is a degeneracy between the neutrino mass and the optical depth to reionisation (tau) in cosmological measurements, we explain clearly the origin of this degeneracy clearly for the first time. In Chapter 3, we extend our study to include forecasted information from future cosmic microwave background (CMB) experiments, including improved E-mode polarisation and CMB lensing measurements. We show that adding optimal primary anisotropy information to our free-streaming constraints strengthens them significantly while still keeping them cosmology-independent. We also show that free-streaming signals in the CMB lensing and galaxy-CMB lensing power spectra can also be isolated to improve free-streaming constraints further. Finally, we show that combined and BAO-only neutrino mass constraints remain strongly cosmology-dependent even when combined with future state-of-the-art CMB measurements. In Chapters 2 and 3, we work exclusively with linear power spectra, which could arguably become invalid on some of the scales we consider. In Chapter 4, we extend our analysis for both galaxy clustering and CMB lensing to make use of next-to-leading-order power spectra. Including next-to-leading-order contributions enhances the free-streaming signature in the power spectrum. However, the large number of additional nuisance parameters in the galaxy power spectrum mean that the final constraints are still somewhat weaker than in the linear case. But most of the qualitative results of the previous chapters hold true, and the free-streaming constraints remain the only cosmology-independent probe of the neutrino mass.Diese Arbeit ist das Ergebnis eines langen Unterfangens, neue Perspektiven und Erkenntnisse für die Herausforderung der Extraktion starker und robuster Neutrinomassenbeschränkungen aus aktuellen und zukünftigen kosmologischen Messungen zu gewinnen. Obwohl die Kosmologie heute die stärksten Einschränkungen für die Neutrinomasse bietet und wahrscheinlich auch weiterhin wird, muss eine entscheidende Priorität sein sicherzustellen, dass diese Beschränkungen für absehbarer Zeit robust genug sind, um auch Wissenschaftler außerhalb der Kosmologie zu überzeugen. Die überwiegende Mehrheit der aktuellen oder prognostizierten kosmologischen Neutrinomassenbeschränkungen in der Literatur gehen bei der Erlangung ihrer Ergebnisse vom konkordanten flachen Lambda-CDM-Modell aus. Trotz der vielen Erfolge ist das Lambda-CDM-Modell nicht ohne Herausforderungen, sowohl theoretischer als auch beobachtbarer Natur. Es ist wichtig, dass alle änderungen, die in Zukunft mit diesem Modell erlangt werden, unsere Neutrinomassenmessungen nicht wesentlich ändern. Das Ziel unserer Arbeit war es, die Bedeutung dieser kosmologischen Annahme zu verstehen, mögliche Entartungen zwischen der Neutrinomasse und anderen kosmologischen Parametern zu verstehen und zu untersuchen, wie viel wir wirklich über die Fähigkeit kosmologischer Messungen zur Messung der Neutrinomasse aussagen können. Wir verfolgen einen semi-analytischen Ansatz unter Verwendung des Fisher-Matrix-Formalismus. In Kapitel 2 dekonstruieren wir gründlich die Beschränkungen der Neutrinomasse, die bei zukünftigen Galaxie-Rotverschiebungsdurchmusterungen zu erlangen sind. Galaxie-Clustering-Messungen reagieren in vielerlei Hinsicht empfindlich auf massive Neutrinos. Wir bieten isolierte Schranken aus Expansionsratenmessungen durch baryonakustische Schwingungen (BAOs) und den Alcock-Paczyński-Test. Wir zeigen auch die einschränkende Wirkung von Redshift-Raumverzerrungen (RSD). Wir entwickeln eine neue Methode zur Isolierung der charakteristischen skalenabhängigen Unterdrückung im Leistungsspektrum als Sonde der Neutrinomasse und zeigen, dass die damit verbundenen Schranken sowohl kosmologieunabhängig als auch relativ stark sind. Wir zeigen, dass alle anderen Einzelproben der Neutrinomasse und der kombinierten Randbedingungen stark kosmologieabhängig sind. Obwohl bereits bekannt war, dass es in kosmologischen Messungen eine Entartung zwischen der Neutrinomasse und der optischen Tiefe zur Reionisation (tau) gibt, erklären wir erstmals deutlich den Ursprung dieser Entartung. In Kapitel 3 erweitern wir unsere Studie um prognostizierte Informationen aus zukünftigen CMB-Experimenten (Cosmic Microwave Background, kosmischer Mikrowellenhintergrund), einschließlich verbesserter E-Moden-Polarisations- und CMB-Gravitationlinsenmessungen. Wir zeigen, dass das Hinzufügen optimaler primärer Anisotropieinformationen zu unseren Freiströmungsbeschränkungen die Neutrinomassenbeschränkungen signifikant verstärkt und gleichzeitig kosmologieunabhängig hält. Wir zeigen auch, dass Freiströmungssignale in den Leistungsspektren der CMB-Gravitationlinsenmessungen und der Galaxie-CMB-Gravitationlinsenmessungen auch isoliert werden können, um die Einschränkungen der Freiströmung weiter zu verbessern. Schließlich zeigen wir, dass kombinierte und reine BAO-Neutrinomassenbeschränkungen auch in Kombination mit zukünftigen modernsten CMB-Messungen stark kosmologieabhängig bleiben. In den Kapiteln 2 und 3 arbeiten wir ausschließlich mit linearen Leistungsspektren, die auf einigen der von uns betrachteten Skalen wohl ungültig werden könnten. In Kapitel 4 erweitern wir unsere Analyse sowohl für Galaxienhaufen als auch für CMB-Linsen, um die Leistungsspektren der nächst höheren Ordnung zu nutzen. Die Einbeziehung von Beiträgen der zweitwichtigsten Ordnung verbessert die Freiströmungssignatur im Leistungsspektrum. Durch die Vielzahl zusätzlicher Störparameter im Leistungsspektrum sind die schlussendlichen Schranken jedoch noch etwas schwächer als im linearen Fall. Aber die meisten qualitativen Ergebnisse der vorangegangenen Kapitel bleiben weiterhin gültig, und die Freiströmungsschranken bleiben der einzige kosmologieunabhängige Test der Neutrino-Masse

Helium in Double-Detonation Models of Type Ia Supernovae

The double-detonation explosion model has been considered a candidate for explaining astrophysical transients with a wide range of luminosities. In this model, a carbon-oxygen white dwarf star explodes following detonation of a surface layer of helium. One potential signature of this explosion mechanism is the presence of unburned helium in the outer ejecta, left over from the surface helium layer. In this paper we present simple approximations to estimate the optical depths of important He I lines in the ejecta of double-detonation models. We use these approximations to compute synthetic spectra, including the He I lines, for double-detonation models obtained from hydrodynamical explosion simulations. Specifically, we focus on photospheric-phase predictions for the near-infrared 10830 \AA~and 2 $\mu$m lines of He I. We first consider a double detonation model with a luminosity corresponding roughly to normal SNe Ia. This model has a post-explosion unburned He mass of 0.03 $M_{\odot}$ and our calculations suggest that the 2 $\mu$m feature is expected to be very weak but that the 10830 \AA~feature may have modest opacity in the outer ejecta. Consequently, we suggest that a moderate-to-weak He I 10830 \AA~feature may be expected to form in double-detonation explosions at epochs around maximum light. However, the high velocities of unburned helium predicted by the model ($\sim 19,000$~km~s$^{-1}$) mean that the He I 10830 \AA~feature may be confused or blended with the C I 10690~\AA~line forming at lower velocities. We also present calculations for the He I 10830 \AA~and 2 $\mu$m lines for a lower mass (low luminosity) double detonation model, which has a post-explosion He mass of 0.077 $M_{\odot}$. In this case, both the He I features we consider are strong and can provide a clear observational signature of the double-detonation mechanism.Comment: 12 pages, 11 figures, accepted by A&

Thomas Wolfe and the genre question: Beyond the "charge of autobiography"

The North Carolinian author Thomas Wolfe (1900‐1938) has long suffered under the “charge of autobiography,” which lingers to this day in critical assessments of his work. Criticism of Wolfe is frequently concerned with questions of generic classification, but since the 1950s, re‐assessments of Wolfe’s work have suggested that Wolfe’s “autobiographical fiction” exhibits a complexity that merits further investigation. Strides in autobiographical and narrative theory have prompted reconsiderations of texts that defy the artificial boundaries of autobiography and fiction. Wolfe has been somewhat neglected in the canon of American fiction of his era, but deserves to be reconsidered in terms of how he engages with the challenges and contradictions of writing about or around the self. This thesis investigates why Wolfe’s work has been the source of considerable critical discomfort and confusion with regard to the relationship between Wolfe’s life and his writing. It explores this issue through an examination of elements of Wolfe’s work that problematise categorisation. Firstly, it investigates the concept of Wolfe as “storyteller.” It explores the motivations and philosophies that underpin Wolfe’s work and his concept of himself as a teller of tales, and examines aspects of Wolfe’s writing process that have their roots in medieval traditions of the memorisation and recitation of tales. The thesis then conducts a detailed examination of how Wolfe describes the process of transforming his memory into narrative through writing. The latter half of the thesis examines narrative techniques used by Wolfe, firstly analysing his extensive use of the iterative and pseudo‐iterative modes, and then his unusual deployment of narrators and focalization. This project sheds light on elements of Wolfe’s approach to writing and narrative strategies that he employs that have previously been overlooked, and that have created considerable critical confusion with regard to the supposedly “autobiographical” genesis of his work

CATALISE: A multinational and multidisciplinary Delphi consensus study. Identifying language impairments in children

© 2016 Bishop et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Delayed or impaired language development is a common developmental concern, yet there is little agreement about the criteria used to identify and classify language impairments in children. Children\u27s language difficulties are at the interface between education, medicine and the allied professions, who may all adopt different approaches to conceptualising them. Our goal in this study was to use an online Delphi technique to see whether it was possible to achieve consensus among professionals on appropriate criteria for identifying children who might benefit from specialist services. We recruited a panel of 59 experts representing ten disciplines (including education, psychology, speech-language therapy/pathology, paediatrics and child psychiatry) from English-speaking countries (Australia, Canada, Ireland, New Zealand, United Kingdom and USA). The starting point for round 1 was a set of 46 statements based on articles and commentaries in a special issue of a journal focusing on this topic. Panel members rated each statement for both relevance and validity on a sevenpoint scale, and added free text comments. These responses were synthesised by the first two authors, who then removed, combined or modified items with a view to improving consensus. The resulting set of statements was returned to the panel for a second evaluation (round 2). Consensus (percentage reporting \u27agree\u27 or \u27strongly agree\u27) was at least 80 percent for 24 of 27 round 2 statements, though many respondents qualified their response with written comments. These were again synthesised by the first two authors. The resulting consensus statement is reported here, with additional summary of relevant evidence, and a concluding commentary on residual disagreements and gaps in the evidence base

CATALISE: A multinational and multidisciplinary Delphi consensus study. Identifying language impairments in children

Delayed or impaired language development is a common developmental concern, yet thereis little agreement about the criteria used to identify and classify language impairments inchildren. Children's language difficulties are at the interface between education, medicineand the allied professions, who may all adopt different approaches to conceptualising them.Our goal in this study was to use an online Delphi technique to see whether it was possibleto achieve consensus among professionals on appropriate criteria for identifying childrenwho might benefit from specialist services. We recruited a panel of 59 experts representingten disciplines (including education, psychology, speech-language therapy/pathology, paediatricsand child psychiatry) from English-speaking countries (Australia, Canada, Ireland,New Zealand, United Kingdom and USA). The starting point for round 1 was a set of 46statements based on articles and commentaries in a special issue of a journal focusing onthis topic. Panel members rated each statement for both relevance and validity on a sevenpointscale, and added free text comments. These responses were synthesised by the firsttwo authors, who then removed, combined or modified items with a view to improving consensus.The resulting set of statements was returned to the panel for a second evaluation(round 2). Consensus (percentage reporting 'agree' or 'strongly agree') was at least 80 percentfor 24 of 27 round 2 statements, though many respondents qualified their responsewith written comments. These were again synthesised by the first two authors. The resultingconsensus statement is reported here, with additional summary of relevant evidence, and aconcluding commentary on residual disagreements and gaps in the evidence base.</p

COVID-19 trajectories among 57 million adults in England: a cohort study using electronic health records

BACKGROUND: Updatable estimates of COVID-19 onset, progression, and trajectories underpin pandemic mitigation efforts. To identify and characterise disease trajectories, we aimed to define and validate ten COVID-19 phenotypes from nationwide linked electronic health records (EHR) using an extensible framework. METHODS: In this cohort study, we used eight linked National Health Service (NHS) datasets for people in England alive on Jan 23, 2020. Data on COVID-19 testing, vaccination, primary and secondary care records, and death registrations were collected until Nov 30, 2021. We defined ten COVID-19 phenotypes reflecting clinically relevant stages of disease severity and encompassing five categories: positive SARS-CoV-2 test, primary care diagnosis, hospital admission, ventilation modality (four phenotypes), and death (three phenotypes). We constructed patient trajectories illustrating transition frequency and duration between phenotypes. Analyses were stratified by pandemic waves and vaccination status. FINDINGS: Among 57 032 174 individuals included in the cohort, 13 990 423 COVID-19 events were identified in 7 244 925 individuals, equating to an infection rate of 12·7% during the study period. Of 7 244 925 individuals, 460 737 (6·4%) were admitted to hospital and 158 020 (2·2%) died. Of 460 737 individuals who were admitted to hospital, 48 847 (10·6%) were admitted to the intensive care unit (ICU), 69 090 (15·0%) received non-invasive ventilation, and 25 928 (5·6%) received invasive ventilation. Among 384 135 patients who were admitted to hospital but did not require ventilation, mortality was higher in wave 1 (23 485 [30·4%] of 77 202 patients) than wave 2 (44 220 [23·1%] of 191 528 patients), but remained unchanged for patients admitted to the ICU. Mortality was highest among patients who received ventilatory support outside of the ICU in wave 1 (2569 [50·7%] of 5063 patients). 15 486 (9·8%) of 158 020 COVID-19-related deaths occurred within 28 days of the first COVID-19 event without a COVID-19 diagnoses on the death certificate. 10 884 (6·9%) of 158 020 deaths were identified exclusively from mortality data with no previous COVID-19 phenotype recorded. We observed longer patient trajectories in wave 2 than wave 1. INTERPRETATION: Our analyses illustrate the wide spectrum of disease trajectories as shown by differences in incidence, survival, and clinical pathways. We have provided a modular analytical framework that can be used to monitor the impact of the pandemic and generate evidence of clinical and policy relevance using multiple EHR sources. FUNDING: British Heart Foundation Data Science Centre, led by Health Data Research UK

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Phase 2 of CATALISE: a multinational and multidisciplinary Delphi consensus study of problems with language development: Terminology.

Background: Lack of agreement about criteria and terminology for children’s language problems affects access to services as well as hindering research and practice. We report the second phase of a study using an online Delphi method to address these issues. In the first phase, we focused on criteria for language disorder. Here we consider terminology.Methods: The Delphi method is an iterative process in which an initial set of statements is rated by a panel of experts, who then have the opportunity to view anonymised ratings from other panel members. On this basis they can either revise their views or make a case for their position. The statements are then revised based on panel feedback, and again rated by and commented on by the panel. In this study, feedback from a second round was used to prepare a final set of statements in narrative form. The panel included 57 individuals representing a range of professions and nationalities. Results: We achieved at least 78% agreement for 19 of 21 statements within two rounds of ratings. These were collapsed into 12 statements for the final consensus reported here. The term ‘Language Disorder’ is recommended to refer to a profile of difficulties that causes functional impairment in everyday life and is associated with poor prognosis. The term, ‘Developmental Language Disorder’ (DLD) was endorsed for use when the language disorder was not associated with a known biomedical aetiology. It was also agreed that (a) presence of risk factors (neurobiological or environmental) does not preclude a diagnosis of DLD, (b) DLD can co-occur with other neurodevelopmental disorders (e.g. ADHD) and (c) DLD does not require a mismatch between verbal and nonverbal ability. Conclusions: This Delphi exercise highlights reasons for disagreements about terminology for language disorders and proposes standard definitions and nomenclature. </p

Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.

BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden