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The role of magnetic cycles in the formation of slingshot prominences
Get PDFSlingshot prominences have been observed on rapidly-rotating cool stars. When they are ejected from a star they carry away mass and angular momentum, and so are important in stellar evolution and spin-down. The observed range of slingshot prominence masses vary by over an order of magnitude. The rate at which prominences form, and the masses that they support, depend on the stellar magnetic field. Several stars have been found to have magnetic cycles with observed dipole reversals similar to the solar magnetic field. This thesis aims to study prominence formation for a range of magnetic cycles and how stellar mass-loss rates are affected. In doing so, this work hopes to contribute to the understanding of variable stellar mass-loss rates and their roles in the evolution of rapidly
rotating stars.
I used solar magnetograms covering the span of one magnetic cycle to simulate the prominence formation for a young solar-type star. In doing so, the variance of prominence masses and locations are found to be the result of interplay between field strength and
the number of stable equilibrium points within the coronal field. Therefore, the total prominence masses and mass-loss rates vary with the magnetic cycle. Expanding this analysis by using simulated magnetograms to create different magnetic cycles, I calculate the total prominence masses for each of the cycle types. I use a flux transport model to create series of magnetograms for four classes of magnetic cycle and identify the similarities and differences in the prominence distributions. I explain the cycle characteristics and prominence distributions in terms of magnetic field strength, topology, and resolution.
This work has implications for characterising magnetic cycles across a range of spectral types, as the variability in prominence formation rates could be an observable link between stellar types and magnetic cycle types. Furthermore, given the potential for prominence ejections to affect planetary atmospheres, the results in this thesis may serve to inform studies on exoplanet habitability by improving our understanding of stellar space-weather
Concurrent bycatch and population assessments of Burmeister's porpoises in northern Peru reveal unsustainable levels of mortality
Get PDFFunding: This project was funded by the International Whaling Commission Small Cetaceans Research Fund to ProDelphinus. C.O.A. was supported by WWF Russel E. Train Fellowship from the World Wildlife Fund (WWF), Programa Nacional de Becas y Crédito Educativo de la República del Perú, and the Handsel Tuition Fee Scholarship from the University of St Andrews.Fisheries-related mortality has been a threat to Burmeister’s porpoises in Peru for decades. However, the magnitude of its impacts on porpoise populations has not been assessed. This study reports the first concurrent abundance and bycatch estimates to evaluate the status of Burmeister’s porpoises in northern Peru. We conducted systematic line transect surveys with 770 km of effort and concurrent towed passive acoustic monitoring as well as semi-structured interviews with gillnet fishers from Salaverry. We recorded 87 porpoise sightings during 9 survey days in February 2023 using a repurposed gillnet fishing vessel and trained observers. Using density surface modelling of the line transect sighting data Burmeister’s porpoise abundance was estimated at 1 696 individuals (CV = 0.23) in the 3 500 km2 study area. Porpoise distribution showed a spatial gradient with highest densities close to shore (<25 km) and in shallow waters (≤50 m). Visual and acoustic detections and fishers’ descriptons of bycatch areas matched closely in space. The majority (66%) of fishers interviewed (n = 32) reported porpoise bycatch in the previous year. For the area matching the abundance survey, the estimated mean bycatch rate per vessel was 6 porpoises/year which equates to an annual bycatch of 420 (95% CI: 210–700) porpoises when scaled to the entire artisanal gillnet fishing fleet of Salaverry. We then considered the potential biological removal reference limit to put into context abundance and bycatch estimates in the study area which shows that current bycatch rates by far exceed sustainable limits and highlights the urgent need for bycatch mitigation measures.Peer reviewe
An approach to population linkage using graph databases
Get PDFFunding: This work was supported by ESRC grants ES/K00574X/2 “Digitising Scotland”, ES/L007487/1 “Administrative Data Research Centre – Scotland”, ES/S007407/1 “Administrative Data Research Centres 2018” and ES/W010321/1 “2022-2026 ADR UK Programme”.We report on a database project which is in the process of linking 29 million vital event records encompassing the entire population of Scotland from 1856 until 1973. Since these records contain no common identifiers, the challenge is to form a pedigree by performing probabilistic linkage over the records. We describe the linkage methodology used to create links between records, for example identifying the birth and marriage records of a single person, and discuss the database technologies employed in the project. A graph database (Neo4j) is used to store both the original vital event records and the links made between them. A metric index is used to find potential links efficiently. Finally, we demonstrate how linkage can be improved by augmenting links based on record distance thresholds with local graph analysis
The role of corporate green bonds in managing greenhouse gas emissions
Get PDFWe investigate the relationship between firms’ green bond issues and the change in their greenhouse gas emissions. We employ an Extended Two-Way Fixed Effects model and the ‘green leverage’ ratio, being the ratio of green bonds to total debt issued, to improve our understanding of the role of green bonds. It shows that greenhouse gas emissions start to decrease significantly three years after issuing a green bond and continue to do so afterwards. This can be explained by the fact that it takes time before new projects – financed by the proceeds of green bonds – have been developed and integrated by the firm issuing the bonds and become fully operational. We conclude that issuing green bonds is a credible signal that communicates firms’ commitment to address climate change to outside investors and other stakeholders.Peer reviewe
Review of Mendieta, Eduardo, The Philosophical Animal: On Zoopoetics and Interspecies Cosmopolitanism
No full textNon peer reviewe
Pour l'écriture de création en French studies
Get PDFThis article is a plea for the inclusion of creative writing in French studies in the UK. It draws on an experiment carried out since 2017 at St Andrews, which began with the creation of the ‘Creative Writing in French’ module and the development of writing workshops in a second language. The collaborative approach adopted by the teaching team leading this project involves bringing into play different versions of complicity: complicity as connivance, as well as in the playful and transgressive connotations of the term – in relation both to the institutional framework that is the university, and to the uses and evolutions of the French language. While practising creative writing in a second language opens up a space of reconfiguration both of teaching and of what is conceived as literature, the notion of ‘horizontal pedagogy’, understood in relation to what Jacques Rancière calls ‘the method of equality’, makes it possible to transform a number of representations of the language into new resources for invention and interpretation. Running the risk of dissonance and divergence, and even embracing this risk, has enabled us to shed light on the poetic possibilities that are brought about by incorrections, mistakes, neologisms, clumsinesses, false friends or else false meanings. The teaching of literature and language as well as current debates about the future of the French language all stand to benefit from these possibilities.Peer reviewe
Ecological recovery of benthic fauna from contamination near oil and gas platforms
Get PDFFunding: CPL, CG, SB, and DJFR were supported by INSITE project EcoSTAR (grant number NE/T010614/1) and NH, CPL, CG, and GT by INSITE project FuECoMMS (grant number NE/T010800/1). CPL was further supported by GES4SEAS (“Achieving Good Environmental Status for maintaining ecosystem services, by assessing integrated impacts of cumulative pressures”, grant agreement no. 101059877, www.ges4seas. eu).Many oil and gas platforms in the North Sea are nearing their end of life and there is an urgent need to understand the legacy effects of associated seabed contamination on benthic communities. We use data from industry-based monitoring surveys, 1985-2015, in a North Sea wide study to investigate change in contaminants and the biomass of benthic functional groups (small infauna, small mobile epifauna, infaunal macrobenthos, and epifaunal macrobenthos). Total hydrocarbon concentrations in sediment samples exceeded 150,000 μg/g between 1992 and 1998 and within 250 m of 6 different platforms. Statistical relationships between chemical concentration, distance from platform and year were modelled using Generalized Additive Mixed Models for 5 environmentally distinct clusters of 236 platforms. Non-linear decreases were identified for total hydrocarbon concentrations as distance from platforms increased for four clusters, but not the deep-water cluster to the north of Scotland. Similarly structured statistical models with benthic biomass as the response variable and total hydrocarbon concentration as the predictor showed that relationships between them varied among clusters and functional groups. Following management measures to reduce contaminant concentrations, the biomass of benthic groups has since returned to reference conditions across many sites. Our results provide a functional perspective that can support ecosystem modelling, inform environmental assessments and support the implementation of management measures. [Abstract copyright: Crown Copyright © 2025. Published by Elsevier Ltd. All rights reserved.]Peer reviewe
2-(Difluoroboryloxy)benzamide
Get PDFThe title compound has been fully characterised by NMR for the first time. Fully assigned 1H and 13C NMR spectra, and the X-ray structure of two different polymorphs are presented. The polymorphs show similar molecular geometries but exhibit significantly different patterns of intermolecular interactions.Peer reviewe
Terrestrial evidence for volcanogenic sulfate-driven cooling event ~30 kyr before the Cretaceous-Paleogene mass extinction
Get PDFFunding: The study was funded by UK Natural Environment Research Council grant NE/S002324/1 awarded to R.M.J., S.K.L., G.D.P., and B.E.v.D. L.K.O. is supported by the Netherlands Earth System Science Centre (grant no. 024.002.001). T.R.L. is supported by the National Science Foundation (NSF-FRES-2317666).Alongside the Chicxulub meteorite impact, Deccan volcanism is considered a primary trigger for the Cretaceous- Paleogene (K-Pg) mass extinction. Models suggest that volcanic outgassing of carbon and sulfur - potent environmental stressors - drove global temperature change, but the relative timing, duration, and magnitude of such change remains uncertain. Here, we use the organic paleothermometer MBT'5me and the carbon-isotope composition of two K-Pg-spanning lignites from the western Unites States, to test models of volcanogenic air temperature change in the ~100 kyr before the mass extinction. Our records show long-term warming of ~3°C, probably driven by Deccan CO2 emissions, and reveal a transient (<10 kyr) ~5°C cooling event, coinciding with the peak of the Poladpur "pulse" of Deccan eruption ~30 kyr before the K-Pg boundary. This cooling was likely caused by the aerosolization of volcanogenic sulfur. Temperatures returned to pre-event values before the mass extinction, suggesting that, from the terrestrial perspective, volcanogenic climate change was not the primary cause of K-Pg extinction.Peer reviewe
Divided minds and divine judgement : dissociative identity disorder, heaven and hell, and the resurrection of the body
Get PDFIn this paper, the author argues that Dissociative Identity Disorder (DID), a disorder in which seemingly independent identities (alters) arise within the same individual, can have considerable consequences in Christian theology. The author shall focus on traditional Christian understandings of the afterlife. The author shall begin by outlining DID, and shall argue that in some DID cases, alters appear to be different persons according to some definitions of personhood in Christian theology. The author shall then illustrate the difficulty this raises for two influential ideas in the Christian tradition: the heaven and hell understanding of the afterlife, and the idea of the resurrection of the body. Finally, the author shall consider some objections to the problem, and shall highlight which responses are the most plausible.Peer reviewe
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