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Changing volatile emissions and sources along the Ethiopian Rift
Get PDFFunding: This work was supported by Global Challenges Research Fund (GCRF) grant to University of St Andrews and Reykjavik Geothermal. W. Hutchison is funded by a UKRI Future Leaders Fellowship (MR/S033505/1). P. Barry acknowledges NSF award 2319897.Rift volcanoes are sites of intense volatile emissions. However, major uncertainties remain about the magnitude of rift volatile fluxes, particularly for greenhouse gases (e.g. CO2) and whether along-rift variations in degassing relate to changing mantle sources and/or rifting processes (i.e. melt production and lithospheric thinning). Here, we investigate CO2 flux and gas isotopes in Ethiopia; a mature, plume-influenced continental rift. We focus on one of the largest caldera volcanoes, Bora-Baricha-Tulu Moye (BBTM), which is situated in a region of high mantle melt production in the Central Main Ethiopian rift (∼500 km south-west the putative plume head). BBTM gases are characterized by plume-like 3He/4He values up to 17 Ra (the highest ever observed in Ethiopian Rift fumaroles) and we calculate total magmatic CO2 flux of 757–901 t d-1 (making BBTM the largest volcanic CO2 emitter in the Ethiopian Rift). Using our CO2 flux measurements, we estimate total CO2 emissions from Ethiopia’s volcanic systems to be 2500–9200 kt yr-1 and reveal important along-rift variation in CO2 flux. High CO2 flux sectors are found in Central Afar, as well as the Northern and Central Main Ethiopian Rift. These sectors are all regions of high partial melt content (evidenced by low seismic velocity in the underlying mantle) and also show the greatest 3He/4He values (>14 Ra). Cooccurrence of high mantle melt production, elevated CO2 emissions and high 3He/4He demonstrates that in mature continental rifts carbon emissions and plume volatile contributions are particularly elevated in regions of greatest lithospheric thinning and mantle melting.Peer reviewe
The use of golf carts as on-course transportation during competitive golf events : a scoping review
Get PDFFunding: Andrew J. Hall received modest funding for the preparation of this article from The R&A and European Tour Group.Background Golf is enjoyed by over 108 million people globally, and has established elite female, male and disability competitive schedules. The use of golf carts during elite competition is a topic of discussion regarding the principles of inclusivity and competitive fairness with important scientific, legal and ethical considerations. Objective The primary aim was to evaluate the evidence relating to riding a golf cart in comparison to walking the golf course, pertaining specifically to: (1) inclusivity and safety, and (2) competitive fairness. The secondary aim was to identify knowledge gaps and research priorities. Methods We conducted a scoping review and the search strategy was applied to the following databases, and articles were extracted by independent reviewers from PubMed, Web of Science, Scopus and ProQuest Central. Grey literature was examined using Google Advanced Search. A five-stage scoping review methodology followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Articles were collated using an online tool (Covidence) and evaluated against pre-determined criteria. Data from included studies were collated to facilitate descriptive and thematic analysis. Results Of the 879 studies identified, 72 were included for analysis. Seven themes emerged: physical demands, inclusion and accessibility, cognitive demands, legal and ethical, nutrition and hydration, competitive fairness, and safety and injury risk. Golf carts promote accessibility, particularly for individuals with disabilities. Safety concerns predominantly arise in non-elite settings, with incidents linked to operator error, poor safety governance and use on public highways. There is compelling evidence demonstrating that in-round riding of golf carts reduces the physical demands of golf, with users expending less energy and covering shorter distances, although effects on performance is uncertain. Golf cart use may mitigate the environmental aspects of golf, including the effects of hot/humid weather or hilly topography. Conclusions Golf carts can increase inclusivity for golfers and enable clubs and organisations to meet their ethical and legal requirements around accessibility. However, riding golf carts may diminish some of the health benefits of golf, and present a risk of injury and practical challenges. In the competitive setting, golf cart use reduces the physical demands of the game, affecting the environmental challenges of variable weather and terrain. It is biologically plausible and likely that this would offer a performance advantage in some circumstances. More research is needed to guide the fair use of this enabling technology within clearly defined contexts by: (1) evaluating the performance deficits associated with medical issues in which the use of golf carts might be considered permissible, and (2) evaluating the magnitude and nature of competitive advantages experienced by golf cart riders.Peer reviewe
A galactic self-portrait : density structure and integrated properties of the Milky Way disk
Get PDFFunding: J.I. gratefully acknowledges support from NSF grant AST-1909897 and STScI DDRF project D0001.82530. J.A.H. also gratefully acknowledges support from NSF grant AST-1909897. N.F.B. acknowledges Science and Technologies Facilities Council (STFC) grant ST/V000861/1. T.C.B acknowledges partial support from grant PHY 14-30152; Physics Frontier Center/JINA Center for the Evolution of the Elements (JINA-CEE), and from OISE-1927130: The International Research Network for Nuclear Astrophysics (IReNA), awarded by the US National Science Foundation. D.B. is partly supported by RSCF grant 22-12-00080. I.M. acknowledges support by the Deutsche Forschungsgemeinschaft under the grant MI 2009/2-1. S.M. has been supported by the LP2021-9 Lendület grant of the Hungarian Academy of Sciences, and by the NKFIH excellence grant TKP2021-NKTA-64.The evolutionary history of the Milky Way disk is imprinted in the ages, positions, and chemical compositions of individual stars. In this study, we derive the intrinsic density distribution of different stellar populations using the final data release of the Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. A total of 203,197 red giant branch stars are used to sort the stellar disk (R ≤ 20 kpc) into subpopulations of metallicity (Δ[M/H] = 0.1 dex), age (Δlog(age/yr) = 0.1), and α-element abundances ([α/M]). We fit the present-day structural parameters and density distribution of each stellar subpopulation after correcting for the survey selection function. The low-α disk is characterized by longer scale lengths and shorter scale heights, and is best fit by a broken exponential radial profile for each population. The high-α disk is characterized by shorter scale lengths and larger scale heights, and is generally well-approximated by a single exponential radial profile. These results are applied to produce new estimates of the integrated properties of the Milky Way from early times to the present day. We measure the total stellar mass of the disk to be 5.27+0.2-1.5 × 1010 M⊙, and the average mass-weighted scale length is Rd = 2.37 ± 0.2 kpc. The Milky Way’s present-day color of (g − r) = 0.72 ± 0.02 is consistent with the classification of a red spiral galaxy, although it has only been in the “green valley” region of the galaxy color–mass diagram for the last ∼3 Gyr.Peer reviewe
Thompson's group T is 3/2-generated
Get PDFFunding: The third-named author was partially supported by the NSF grant DMS–2005297.Every finite simple group can be generated by two elements and, in fact, every nontrivial element is contained in a generating pair. Groups with this property are said to be 3/2-generated, and the finite 3/2-generated groups were recently classified. Turning to infinite groups, in this paper, we prove that the finitely presented simple group T of Thompson is 3/2-generated. Moreover, we exhibit an element ζ ∈ T such that for any nontrivial α ∈ T, there exists γ ∈ T such that ⟨α, ζγ⟩ = T.Peer reviewe
The potential of extended reality in Rural Education’s future – perspectives from rural educators
Get PDFFunding: This study is funded by Trinity College Dublin-China Scholarship Council Joint Scholarship. This publication has also emanated from research conducted with the financial support of the European Union as part of the Horizon Europe Framework Program (HORIZON) under grant agreement 101070109.Technology-enhanced education can potentially enhance teaching and learning outcomes for rural educators since they face limited educational resources and low job satisfaction. Recently, there has been a surge in extended reality (XR) as an immersive learning technology to improve teaching and learning in rural areas, but without focusing on rural educators’ perspectives. This study aims to bridge this gap by investigating rural educators’ interactions with XR educational applications and exhibiting their insights on using XR education to improve education quality in rural areas. After educators’ hands-on experiences in a pre-designed XR education workshop, qualitative data was collected from their discussions in focus groups. As a result, educators believed that XR could transform traditional educational practices and create opportunities for new patterns of rural education (e.g., public engagement with rurality and rural vocational education). Limitations include a lack of school infrastructure to apply XR and an absence of well-structured curriculum design to use XR in the classroom setting. We suggest that future studies explore the integration of effective XR practices into primary and elementary education in those areas with limited educational resources.Peer reviewe
Anti-Calvinism and the Ayrshire enlightenment
Get PDFThis essay locates Burns in the context of the intense and combative ecclesiastical politics of Ayrshire during the second half of the eighteenth century, a period when the county saw not only a culture of robust pamphleteering on theological matters but also a couple of high-profile heresy trials. Whereas the Scottish Enlightenment as a whole was, the issue of lay patronage apart, a relatively sedate affair which—surprisingly—witnessed no major theological controversies over subscription to the Calvinist doctrines enshrined in the Westminster Confession of Faith (1647), Ayrshire was a disputatious outlier from those consensual norms. There was a marked theological gulf in Burns’s Ayrshire between hardline Calvinist ‘auld lichts’ and theologically liberal anti-Calvinist ‘new lichts’, including the Reverend William McGill of Ayr, who was tried for heresy, and the polymathic layman John Goudie of Kilmarnock, who published a direct attack on the doctrine of original sin which Burns celebrated in verse. Burns’s ecclesiastical satires emerged in a local environment of vigorous, vicious and personalized theological debate, much of it focused on the core doctrines of Calvinism
Disks around young free-floating planetary-mass objects : ultradeep Spitzer imaging of IC348
No full textFunding: AS acknowledges support from the UKRI Science and Technology Facilities Council through grant ST/Y001419/1/.Protoplanetary discs have been found around free-floating objects with masses comparable to those of giant planets. The frequency and properties of these discs around planetary-mass objects are still debated. Here, we present ultradeep mid-infrared images for the young cluster IC348, obtained through stacking of time-series images from Spitzer. We measure fluxes at 3.6 and 4.5 μm for known free-floating planetary-mass objects (FFPMOs, spectral type M9 or later) in this cluster. By comparing the observed infrared spectral energy distributions with photospheric templates, we identify six planetary-mass objects with discs, plus three, which may or may not have a disc. This corresponds to a disc fraction of 46-12+13 per cent. The disc fraction among planetary-mass objects is comparable to more massive brown dwarfs. We show the disc fraction among FFPMOs as a function of age, demonstrating that these objects retain discs for several million years, similar to low-mass stars and brown dwarfs.Peer reviewe
Mechanistic insights into Cs-ion Exchange in the zeolite chabazite from in situ powder X-ray diffraction
Get PDFFunding: The research at Diamond was funded by the EPSRC under Grant No. EP/V027387/1 and that at St. Andrews under Grant No. EP/R513337/1.Zeolites contain extraframework cations that are exchangeable under favorable aqueous conditions; this is the fundamental feature for their application in water purification and necessary to produce cation forms for other applications such as catalysis. Optimization of the process is common, but there is little fundamental understanding based on real-time experiments of the mechanism of exchange for most zeolites. The sodium and potassium forms of zeolite chabazite selectively uptake Cs+ by ion exchange, leading to its application in removing radioactive 137Cs+ from industrial nuclear waste streams, as well as from contaminated environments in the aftermath of the Fukushima and Three Mile Island accidents. In this study, in situ synchrotron powder X-ray diffraction patterns have been collected on chabazite as it undergoes Cs-ion exchange. Applying Rietveld refinement to these patterns has revealed the time-resolved structural changes that occur in the zeolite as exchange progresses, charting the changes in the spatial distribution of the extraframework cations and water molecules in the structure during the reaction. Ultimately, a detailed mechanistic understanding of how this dynamic ion-exchange reaction occurs has been obtained.Peer reviewe
Boron isotope pH calibration of a shallow dwelling benthic nummulitid foraminifera
Get PDFFunding: The foraminifera culturing was funded by NSF-BSF project 1634573 and by ISF project 790/16 and 1886/20 to Jonathan Erez. FIERCE is financially supported by the Wilhelm and Else Heraeus Foundation and by the Deutsche Forschungsgemeinschaft (DFG: INST 161/921-1 FUGG, INST 161/923-1 FUGG and INST 161/1073-1 FUGG), which is gratefully acknowledged. This research was funded through the VeWA research consortium (Past Warm Periods as Natural Analogues of our high-CO2 Climate Future) by the LOEWE programme of the Hessen Ministry of Higher Education, Research and the Arts, Germany, and also by the RSE, Saltire International Collaboration Award number 1964.The boron isotope palaeo-pH/CO2 proxy is one of the key quantitative tools available to reconstruct past changes in the concentration of CO2 in the atmosphere. In particular, marine calcifying organisms have been shown to be useful archives of this proxy, enabling quantitative variations in pH/CO2 to be reconstructed throughout the Cenozoic. In order to provide an alternative proxy archive to the widely used planktonic foraminifera, we investigated the symbiont-bearing, high-Mg, shallow-dwelling, tropical large benthic foraminifera (LBF) species Operculina ammonoides and present a calibration of the relationship between the shell boron isotopic composition and seawater pH. We investigated specimens collected from both several reefs as well as grown in laboratory culture experiments in which pH and DIC were decoupled from each other, measuring newly-formed chambers using laser-ablation as a sample introduction technique. Based on our laboratory culture samples, the resulting linear relationship between the in situ boron isotopic composition of aqueous borate ion (B(OH)4−) and the shells of O. ammonoides is characterised by a gradient of 0.38-0.10+0.12. In contrast, the boron isotopic composition of the field collected samples displays a near 1:1 relationship with B(OH)4−. We suggest that the shallow slope of the laboratory culture regression is the result of the difference between their micro-environment carbonate chemistry and that of the surrounding seawater driven by a pH dependence of the relative rates of calcification and photosynthesis. Based on a model of the effect of these processes on the diffusive boundary layer, we show that this effect is expected in laboratory culture experiments free from micro-turbulence, but not in the foraminifer’s natural environment. As such, we demonstrate the utility of these organisms as proxy archive, while also highlighting how laboratory experimental design has the potential to drive important changes in the micro-environment and resulting shell chemistry of organisms of this size. Given that the genus Operculina originated in the late Palaeocene, this work paves the way towards deep-time palaeo-pH/CO2 reconstructions using foraminifer species which have a very closely related modern representative.Peer reviewe
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