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Capturing local compositional fluctuations in NMR modelling of solid solutions
No full textFunding: The authors are grateful to EPSRC for support through the Collaborative Computational Project on NMR Crystallography (CCP-NC), via EP/M022501/1, the UKCP consortium (EP/K013564/1) and for studentship support for BLG on EP/R513337/1. TDS acknowledges support from the Royal Society Wolfson Visiting Fellowship program and Ramsey Issa acknowledges support from Ultradent Products Inc. Collaboration between RGC and SH was supported by Action CA18234 (CompNanoEnergy) funded by COST (European Cooperation in Science and Technology). We acknowledge the ERC (EU FP7 Consolidator Grant 614290 ‘EXONMR’) for support for SEA, AF, RFM and DM. S.R.G.B. thanks the Spanish Ministry of Science Innovation MCIN/AEI/10.13039/501100011033 (grant RYC2022-036070-I).Understanding the atomic-scale local properties of solid solutions is crucial for deciphering their structure–property relationships. In this work, we present a computational approach that combines solid-state nuclear magnetic resonance (NMR) spectroscopy with density functional theory (DFT) calculations to investigate local chemical environments in solid solutions. Previous canonical ensemble models, which only sample configurations at a fixed composition of the simulation cell, fail to capture local compositional fluctuations that can significantly influence the NMR spectra. To address this limitation, we employ a grand-canonical ensemble approach enabling a more comprehensive representation of the contributions of all possible local chemical environments to the NMR spectrum, using a La2(Zr1−xSnx)2O7 pyrochlore solid solution as a case study. To mitigate the high computational cost of such simulations, we also explore ensemble truncation strategies and the use of machine learning (ML) to aid predictions of NMR chemical shifts, achieving a significant reduction in computational cost while maintaining most of the predictive power. Our results show that combining the grand-canonical approach with machine learning and ensemble truncation offers an efficient framework for modelling and interpreting NMR spectra in disordered crystalline materials.Peer reviewe
Gaussian process modelling of infectious diseases using the Greta software package and GPUs
Get PDFGaussian process are a widely-used statistical tool for conducting non-parametric inference in applied sciences, with many computational packages available to fit to data and predict future observations. We study the use of the Greta software for Bayesian inference to apply Gaussian process regression to spatio-temporal data of infectious disease outbreaks and predict future outbreaks. Greta builds on Tensorflow, making it comparatively easy to take advantage of the significant gain in speed offered by GPUs. In these complex spatio-temporal models, we show a reduction of up to 70% in computational time relative to fitting the same models on CPUs. We show how the choice of covariance kernel impacts the ability to infer spread and extrapolate to unobserved spatial and temporal units. The inference pipeline is applied to weekly incidence data on tuberculosis in the East and West Midlands regions of England over a period of two years.Peer reviewe
Timescales of magmatic-hydrothermal tin mineralisation in the Cornubian Orefield, SW England
No full textTin has been classed as a critical metal for over a decade, with demand rising due to its role in the green energy transition. Mined predominately as cassiterite (SnO₂), primary tin deposits form from magmatic-hydrothermal processes commonly associated with late-stage, evolved granitic melts. These systems develop over 10s Myrs from multiple discrete magmatic and hydrothermal events, but the timing of Sn-mineralisation within the long emplacement history of granite batholiths remain poorly constrained, largely due to limitations in traditional geochronological methods. This thesis applies U-Pb geochronological techniques - isotope dilution thermal ionisation mass spectrometry (ID-TIMS) and laser ablation inductively coupled mass spectrometry (LA-ICP-MS) - to date cassiterite to produce an updated mineralisation geochronological framework across the Cornubian Orefield, SW England.
The U-Pb systematics of nine cassiterite reference materials were further characterised by ID-TIMS. Three materials produced repeatable lower intercept ages and were used as primary and secondary reference materials within a matrix-matched LA-ICP-MS approach.
Twenty-eight cassiterite samples from across the Cornubian Orefield were analysed by LA-ICP-MS. The cassiterite dates show that tin mineralisation spanned the entire construction history of the Cornubian Batholith between ca. 293 - 275 Ma, with a period of high tin deposition at <282 Ma. The contemporaneous nature of cassiterite with host magmatism (within ±4 Ma) suggests multiple parental magmatic sources such that tin formed in association with both the lower and higher temperature dehydration melting of muscovite and biotite mica.
High-precision ID-TIMS dating of cassiterite and magmatic zircon from the South Crofty Mine revealed: 1) host magmatism was generally unrelated to cassiterite-bearing lodes; 2) lode formation commenced ~4 Myrs post host granite emplacement; 3) lode formation occurred during two distinct mineralising events at ca. 288 Ma and 280 Ma. Thus, both regionally and within a single mined deposit, cassiterite-bearing lodes have multiple parental magmas, likely facilitated by the continuous regional extensional and prolonged magmatism."This work was financially supported by the Natural Environmental Research Council (NERC) IAPETUS2 DTP (Grant Number: NE/S007431/1); and a National Environmental Isotope Facility grant (NEIF - 2723.0923)."--Fundin
CAVITY, Calar Alto Void Integral-field Treasury surveY and project extension
Get PDFFunding: We acknowledge financial support by the research projects AYA2017-84897-P, PID2020-113689GB-I00, and PID2020-114414GB-I00, financed by MCIN/AEI/10.13039/501100011033, the project A-FQM-510-UGR20 financed from FEDER/Junta de Andalucía-Consejería de Transformación Económica, Industria, Conocimiento y Universidades/Proyecto and by the grants P20-00334 and FQM108, financed by the Junta de Andalucía (Spain). TRL acknowledges support from Juan de la Cierva fellowship (IJC2020-043742-I). LSM acknowledges support from Juan de la Cierva fellowship (IJC2019-041527-I). DE acknowledges support from a Beatriz Galindo senior fellowship (BG20/00224) from the Spanish Ministry of Science and Innovation. RGD, RGB, and AC acknowledge financial support from the State Agency for Research of the Spanish MCIU through ‘Center of Excellence Severo Ochoa’ award to the Instituto de Astrofísica de Andalucía, CEX2021-001131-S, funded by MCIN/AEI/10.13039/501100011033, and to financial support from the projects PID-2019-109067-GB100 and PID2022-141755NB-I00. HC also acknowledges support from the Institut Universitaire de France and from the CNES. IMC acknowledges support from ANID programme FONDECYT Postdoctorado 3230653. JF-B acknowledges support from the PID2022-140869NB-I00 grant from the Spanish Ministry of Science and Innovation. VQ,SP, and MH acknowledge that this work has been supported by the Agencia Estatal de Investigación Española (AEI; grant PID2022-138855NB-C33), by the Ministerio de Ciencia e Innovación (MCIN) within the Plan de Recuperación, Transformación y Resiliencia del Gobierno de España through the project ASFAE/2022/001, with funding from European Union NextGenerationEU (PRTR-C17.I1), and by the Generalitat Valenciana (grant PROMETEO CIPROM/2022/49). PSB acknowledges financial support from the from the Spanish Ministry of Science under the projects with references: PID2019-107427GB-C31 and PID2022-138855NB-C31. PVG acknowledges that the project that gave rise to these results received the support of a fellowship from “la Caixa” Foundation (ID 100010434). The fellowship code is B005800. AFM acknowledges support from RYC2021-031099-I and PID2021-123313NA-I00 of MICIN/AEI/10.13039/501100011033/FEDER, UE, NextGenerationEU/PRT. M.A-F. acknowledges support from the Emergia program (EMERGIA20-38888) from Consejería de Universidad, Investigación e Innovación de la Junta de Andalucía. JR acknowledges funding from University of La Laguna through the Margarita Salas Program from the Spanish Ministry of Universities ref. UNI/551/2021-May 26, and under the EU Next Generation. BB acknowledges financial from the Grant AST22_4.4, funded by Consejería de Universidad, Investigación e Innovación and Gobierno de España and Unión Europea – NextGenerationEU, and by the research project PID2020-113689GB-I00 financed by MCIN/AEI/10.13039/501100011033. GTR acknowledges financial support from the research project PRE2021-098736, funded by MCIN/AEI/10.13039/501100011033 and FSEs.We have learnt in the last decades that the majority of galaxies belong to high density regions interconnected in a sponge-like fashion. This large-scale structure is characterised by clusters, filaments, and walls, where most galaxies concentrate, but also under-dense regions called voids. The void regions and the galaxies within represent an ideal place for the study of galaxy formation and evolution, as they are largely unaffected by the complex physical processes that transform galaxies in high-density environments. The void galaxies may hold the key to answer current challenges to the ΛCDM paradigm as well. The CAVITY survey is a Legacy project approved by the Calar Alto Observatory to obtain spatially resolved spectroscopic information of ∼300 void galaxies in the Local Universe (0.005 < z < 0.050), covering −17.0 to −21.5 in r band absolute magnitude. It officially started in January 2021 and has been awarded 110 useful dark observing nights at the 3.5 m telescope using the PMAS spectrograph. Complementary follow-up projects, including deep optical imaging, integrated as well as resolved CO data, and integrated HI spectra, have joined the PMAS observations and naturally complete the scientific aim of characterising galaxies in cosmic voids. The extension data has been named CAVITY+. The data will be available to the whole community in different data releases, the first of which is planned for July 2024, and it will provide the community with PMAS datacubes for around 100 void galaxies through a user friendly and well documented database platform. Here, we present the survey, sample selection, data reduction, quality control schemes, science goals, and some examples of the scientific power of the CAVITY and CAVITY+ data.Peer reviewe
Planetary sources of bio-essential nutrients on a prebiotic world
Get PDFFunding: Marie Curie - EP/Y026497/1; Natural Environment Research Council - NE/V010824/1; UK Space Agency - ST/W002337/1Multiple bio-essential elements such as nitrogen and phosphorus are found in all forms of life discovered thus far. In addition to these major elements, many transition metals have been proposed as crucial components for prebiotic and early cellular processes. These elements must, therefore, have been available during the origin of life; however, the processes that mobilized them on the prebiotic Earth likely differed from today. We provide a review and discussion on planetary processes that influenced the availability of bio-essential elements on early Earth and propose the most likely environments to host key prebiotic reactions and perhaps primitive life, based on their supply of nitrogen, phosphorus and transition metals. In particular, terrestrial acidic hot spring systems and deep-sea hydrothermal vents may have created ideal conditions through abiotic nitrogen reduction, dissolution of reactive phosphorus species and leaching of siderophilic transition metals from igneous bedrocks. This concept has implications far beyond Hadean Earth, as similar geothermal systems once existed on the surface of Noachian Mars, providing a comparable suite of elements, suggesting that crucial steps towards an independent origin of life may have unfolded on Mars and perhaps other terrestrial planets.Peer reviewe
Neural oscillatory markers of voluntary task switching : proactive engagement of self-directed control in children and adults
Get PDFFunding: This research was funded by a doctoral scholarship from Suor Orsola Benincasa University and Research Grant Support from the University of Edinburgh awarded to Aurélien Frick.Cognitive control shows two main developmental trends: greater self-directedness (i.e., children need less external scaffolding) and greater proactiveness (i.e., children increasingly anticipate and prepare for upcoming cognitive demands). The present study examined potential links between these major developmental transitions. Specifically, it used EEG oscillations to investigate the extent to which children, like adults, engage self-directed control in a proactive fashion, and whether age-related changes reflect progress in task selection, motor preparation, or both. Five-6-year-olds, 9-10-year-olds, and adults performed a voluntary task-switching paradigm in which visual support for past actions was manipulated. Both children and adults showed greater frontolateral delta/theta power and lower central mu power on switch than repeat trials, but visual support differentially affected these oscillatory markers across age groups. Children already engage self-directed control proactively from 5-6 years of age in the voluntary task-switching paradigm, albeit differently than adults, suggesting close links between self-directed and proactive control developmentsPeer reviewe
Rooted in routine : fostering higher order vegetable-shopping habits using a randomised simple planning intervention
Get PDFFunding: This work was supported by the Royal Society of Edinburgh (RSE Reference Number: 2374) (Personal Research Fellowship for Dr. Kimberly R. More).A healthy diet is a protective factor against a host of negative health outcomes. To maintain such a diet necessitates the consumption of at least 240 g of vegetables per day. However, most of the population fails to meet this threshold. Utilising a randomised controlled trial, the present study tested the effectiveness of a one-off higher order habit intervention aimed at shopping for a variety of vegetables and the mechanisms that may support such habit development. Specifically, participants (N = 198; 54.5% female; 20 to 74 years of age) were allocated to the intervention or control group to explore (1) how effective an action- and coping-planning intervention is at targeting the formation of vegetable-shopping higher order habits and (2) whether healthy-eater identity, intrinsic motivation and self-efficacy were mechanisms of action. Follow-up measures of habit, the mechanisms of action and behaviour were taken post-intervention, weekly for 4 weeks and at 3- and 6-month follow-ups. The intervention led to stronger higher order habit formation after 6 months and that it was particularly effective for those with low baseline higher order habits for vegetable shopping. These findings demonstrate that a simple, one-off, intervention can lead to long-lasting change in higher order habits within the nutrition domain.Peer reviewe
Variation in wood density across South American tropical forests
Get PDFFunding: Funding: For supporting the networks, we thank the European Research Council (ERC Advanced Grant 291585 – ‘T-FORCES’), the Gordon and Betty Moore Foundation (#1656 ‘RAINFOR’, and ‘MonANPeru’), the European Union’s Fifth, Sixth and Seventh Framework Programme (EVK2-CT-1999-00023 – ‘CARBONSINK-LBA’, 283080 – ‘GEOCARBON’, 282664 – ‘AMAZALERT), the Natural Environment Research Council (NE/ D005590/1 – ‘TROBIT’, NE/F005806/1 – ‘AMAZONICA’, E/M0022021/1 - ‘PPFOR’), several NERC Urgency and New Investigators Grants, the NERC/State of São Paulo Research Foundation (FAPESP) consortium grants ‘BIO-RED’ (NE/N012542/1), ‘ECOFOR’ (NE/K016431/1, 2012/51872-5, 2012/51509-8), ‘ARBOLES’ (NE/S011811/1, FAPESP 2018/15001-6), ‘SEOSAW’ (NE/P008755/1), ‘SECO’ (NE/T01279X/1), Brazilian National Research Council (PELD/CNPq 403710/2012-0), the Royal Society (University Research Fellowships and Global challenges Awards) (ICA/R1/180100 - ‘FORAMA’), the National Geographic Society, US National Science Foundation (DEB 1754647) and Colombia’s Colciencias. We thank the National Council for Science and Technology Development of Brazil (CNPq) for support to the Cerrado/Amazonia Transition Long-Term Ecology Project (PELD/441244/2016-5), the PPBio Phytogeography of Amazonia/Cerrado Transition Project (CNPq/PPBio/457602/2012-0), PELD-RAS (CNPq, Process 441659/2016-0), RESFLORA (Process 420254/2018-8), Synergize (Process 442354/2019-3), the Empresa Brasileira de Pesquisa Agropecuária – Embrapa (SEG: 02.08.06.005.00), the Fundação de Amparo à Pesquisa do Estado de São Paulo – FAPESP (2012/51509-8 and 2012/51872-5), the Goiás Research Foundation (FAPEG/PELD: 2017/10267000329) the EcoSpace Project (CNPq 459941/2014-3), PELD 441572/2020-0, the FATE project (03/12595-7) and several PVE and Productivity Grants. We also thank the “Investissement d’Avenir” program (CEBA, ref. ANR-10LABX-25-01), the São Paulo Research Foundation (FAPESP 03/12595-7, 2016/21043-8) and the Sustainable Landscapes Brazil Project (through Brazilian Agricultural Research Corporation (EMBRAPA), the US Forest Service, USAID, and the US Department of State) for supporting plot inventories in the Atlantic Forest sites in Sao Paulo, Brazil. We thank to the National Council for Technological and Scientific Development (CNPq) for the financial support of the PELD project (441244/2016-5, 441572/2020-0) and FAPEMAT (0346321/2021). We thank Reserva Particular do Patrimônio Natural Serra das Almas for supporting our research at the reserve. This paper also includes plots where recensuses and data assimilation were funded by SECO (NE/T01279X/1), and plots established by Darwin Initiative funded project 20-021, NERC-Newton-FAPESP project Nordeste (NE/N01247X/1; NE/N012550/1) and the USAID funded Partnerships for Enhanced Engagement in Research project. This manuscript is an output of ForestPlots.net Research Project 75A. “Mapping LATAM Forest Wood Density”, which is part of the NERC-FAPESP funded project ARBOLES (NE/S011811/1). ForestPlots.net is a meta-network and cyber-initiative developed at the University of Leeds that unites permanent plot records and supports tropical forest scientists. We acknowledge the contributions of the ForestPlots.net Collaboration and Data Request Committee (B.S.M., E.N.H.C., O.L.P., T.R.B., B. Sonké, C. Ewango, J. Muledi, S.L.L., L. Qie) for facilitating this project and associated data management. The development of ForestPlots.net and curation of data has been funded by several grants including NE/B503384/1, NE/N012542/1 - ‘BIO-RED’, ERC Advanced Grant 291585 - ‘T-FORCES’, NE/F005806/1 - ‘AMAZONICA’, NE/N004655/1 - ‘TREMOR’, NERC New Investigators Awards, the Gordon and Betty Moore Foundation (‘RAINFOR’, ‘MonANPeru’), ERC Starter Grant 758873 -‘TreeMort’, EU Framework 6, a Royal Society University Research Fellowship, and a Leverhulme Trust Research Fellowship. For supporting M.S. we thank NERC (NE/N012542/1 and NE/W003872/1) and the Royal Society (a Royal Society Global Challenges grant “Sensitivity of Tropical Forest Ecosystem Services to Climate Changes”). F.E. was supported by BJT-FAPESPA Program (Process No. 2021/658588) and the Serrapilheira Institute fellowship/FAPESPA (grant number – R-2401–46863), T.F.D. received support from the Brazilian National Council for Scientific and Technological Development (CNPq - 312589/2022-0 Research Productivity Grant) and FAPESP grant 2015/50488-5, G.W.F was supported by APQ 00031-19 FAPEMIG/Renova and J.P. was supported by a CNPq productivity scholarship (312571/2021-6).Wood density is a critical control on tree biomass, so poor understanding of its spatial variation can lead to large and systematic errors in forest biomass estimates and carbon maps. The need to understand how and why wood density varies is especially critical in tropical America where forests have exceptional species diversity and spatial turnover in composition. As tree identity and forest composition are challenging to estimate remotely, ground surveys are essential to know the wood density of trees, whether measured directly or inferred from their identity. Here, we assemble an extensive dataset of variation in wood density across the most forested and tree-diverse continent, examine how it relates to spatial and environmental variables, and use these relationships to predict spatial variation in wood density over tropical and sub-tropical South America. Our analysis refines previously identified east-west Amazon gradients in wood density, improves them by revealing fine-scale variation, and extends predictions into Andean, dry, and Atlantic forests. The results halve biomass prediction errors compared to a naïve scenario with no knowledge of spatial variation in wood density. Our findings will help improve remote sensing-based estimates of aboveground biomass carbon stocks across tropical South America.Peer reviewe
Problems and solutions when quantifying nitrogen in silicate and oxide minerals and glasses using electron probe microanalysis
Get PDFFunding: EES was supported by a NERC Frontiers grant (NE/V010824/1), and ERM and SM were supported a NERC standard grant (NE/PO12167/1) and a Carnegie Trust Research Incentive Grant (RIG007794). The authors acknowledge Microscopy Australia (ROR: 042mm0k03) at the Centre for Advanced Microscopy, The Australian National University, a facility enabled by NCRIS and university support.With growing interest in the Earth's deep nitrogen cycle, electron probe microanalysis is increasingly used to quantify nitrogen in minerals and glasses. However, measuring nitrogen by electron microprobe comes with challenges, including beam sensitivity and differences in peak and background shapes between sample and reference materials. This study provides a robust analytical protocol to addresses these issues. We gathered mineral and glass reference materials with known nitrogen mass fractions from previous work, and synthesised additional glasses with nitrogen quantified independently by gas-source mass spectrometry. Our method uses nitrides as calibration materials because of their beam stability and high nitrogen mass fraction. We assess peak shapes to implement an area-peak factor correction, and account for curved backgrounds using a four-point background correction. Importantly, we describe how to estimate uncertainties on both background and area-peak factor corrections, which is required to assess detection limits but has been largely overlooked in previous studies. Our method yields nitrogen mass fractions within uncertainty for five out of seven reference materials, with two exceptions highlighting the need for further refinement. We provide Python code for applying the corrections and calculating uncertainties, allowing our method to be implemented by any researcher with access to an electron microprobe laboratory.Peer reviewe
Spatial modelling and mapping of urban fire occurrence in Portugal
Get PDFFunding: This work is funded by national funds through the FCT - Fundação para a Ciência e a Tecnologia, I.P., under the scope of the project DSAIPA/DS/0088/2019 and research and development units UNIDEMI (project UIDB/00667/2020) and NOVAMath (projects UIDB/00297/2020 and UIDP/00297/2020).Fires in urban areas typically carry severe consequences. High population density together with the complexity of urban network potentially imply significant impacts in property loss, physical damage and life losses. However, despite the impact that fires may have in urban areas, research in urban fire prediction remains limited. In this study, we modelled urban fire occurrences while making a comparative analysis of different strategies to account for spatial autocorrelation. Considering space dependence in addition to a range of social-economic explanatory variables has proven to strengthen the validity of the fitted models. The spatial Durbin error model, including population density, degraded buildings density and buying power, was selected as having the best fit. This model allowed to map the estimated probability of fire occurrence across Portugal, revealing a spatial pattern with clusters centred on the two main Portuguese city districts (Lisboa and Porto). Ultimately, the analysis of the relation between the observed urban fire incidence and the actual number of fire stations in each municipality allowed to underline the need for planning the spatial configuration of fire stations, both in number and location, at a regional scale.Peer reviewe
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