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Isotopically heavy sulfur in nephelinite from Etinde, Cameroon Volcanic Line : implications for the origin of intraplate magmatism
Get PDFFunding: S. Baldwin acknowledges funding from the E4 NERC doctoral training partnership (DTP) grant NE/S007407/1. W. Hutchison is funded by a UKRI Future Leaders Fellowship MR/S033505/1. E. Stüeken is funded by a NERC Frontiers grant NE/V010824/1.Intraplate magmatism has traditionally been linked to anomalously hot mantle (hotspots) transported upwards from deep-sourced mantle plumes. However, many intraplate magmatic provinces lack convincing evidence for a mantle-plume origin, and the Cameroon Volcanic Line (CVL) located on the West African continental margin is one such province. Despite being active for ca. 65 million years, it lacks the time-progressive volcanic activity that would suggest the presence of a fixed mantle hotspot or plume; instead CVL magmatism has been linked to a shallow, enriched asthenospheric source. Etinde, a relatively young (<1 Ma) volcano located at the centre of the CVL on the continent-ocean boundary, is the most silica-undersaturated and incompatible element-enriched volcano in the region and forms the focus of this study. It is constructed almost entirely of feldspar-free nephelinite lava flows, with compositions ranging from olivine nephelinite to felsic leucite nephelinite. We report new sulfide-, sulfate- and bulk-δ34S data for a suite of Etinde rock samples; the first sulfur-isotope data for the CVL. Strong (∼8 ‰) S-isotope fractionation between sulfide and sulfate (haüyne, nosean) phases suggest equilibration temperatures of ∼600 °C, well below the magma solidus temperature and likely due to sub-solidus exsolution of nanoscale sulfide particles from the sulfate phenocryst phases. The most mafic samples from Etinde have been extensively degassed, containing less than 60 ppm sulfur, and therefore cannot be used to constrain the primary δ34S. Instead, we use the intermediate and felsic volcanic rocks, where sulfur is locked in phenocrysts of haüyne and nosean, respectively. Bulk δ34S of these rocks, which best represents the primary magmatic values, ranges from +3.7 ‰ to +6.3 ‰, a heavier signature than previously reported in alkaline igneous rocks. We propose that the heavy sulfur isotope values, together with the extreme silica undersaturation and incompatible element concentrations, reflect enrichment of the mantle source and fingerprint carbonate metasomatism in the mantle beneath the CVL. The heavy sulfur isotopic signature requires low-temperature fractionation and therefore implies the addition of sulfur through subduction processes. Our study has broad geochemical significance in contributing to a growing understanding of sulfur-isotope compositional variability in geochemically enriched mantle globally.Peer reviewe
Improved pretreatments and fractionation of soft and hardwoods to access feedstock chemicals
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The NAD+ precursor nicotinamide riboside rescues mitochondrial defects and neuronal loss in iPSC derived cortical organoid of Alpers' disease
Get PDFFunding: This work was supported by the following funding: K.L was partly supported by University of Bergen Meltzers Høyskolefonds (#103517133) and Gerda Meyer Nyquist Legat (#103816102). L.A.B was supported the Norwegian Research Council (#229652), Rakel og Otto Kr.Bruuns legat. G.J.S was partly supported by the Norwegian Research Council through its Centres of Excellence funding scheme (#262613). E.F.F. is supported by Cure Alzheimer's Fund (#282952), HELSE SØR-ØST (#2020001, #2021021, #2023093), the Research Council of Norway (#262175, #334361), Molecule AG/VITADAO (#282942), NordForsk Foundation (#119986), the National Natural Science Foundation of China (#81971327), Akershus University Hospital (#269901, #261973, #262960), the Civitan Norges Forskningsfond for Alzheimers sykdom (#281931), the Czech Republic-Norway KAPPA programme (with Martin Vyhnálek, #TO01000215), and the Rosa sløyfe/Norwegian Cancer Society & Norwegian Breast Cancer Society (#207819). Z.Y.Z. is supported by the National Natural Science Foundation of China (#82103460).Alpers' syndrome is an early-onset neurodegenerative disorder usually caused by biallelic pathogenic variants in the gene encoding the catalytic subunit of polymerase-gamma (POLG), which is essential for mitochondrial DNA (mtDNA) replication. The disease is progressive, incurable, and inevitably it leads to death from drug-resistant status epilepticus. The neurological features of Alpers' syndrome are intractable epilepsy and developmental regression, with no effective treatment; the underlying mechanisms are still elusive, partially due to lack of good experimental models. Here, we generated the patient derived induced pluripotent stem cells (iPSCs) from one Alpers' patient carrying the compound heterozygous mutations of A467T (c.1399G>A) and P589L (c.1766C>T), and further differentiated them into cortical organoids and neural stem cells (NSCs) for mechanistic studies of neural dysfunction in Alpers' syndrome. Patient cortical organoids exhibited a phenotype that faithfully replicated the molecular changes found in patient postmortem brain tissue, as evidenced by cortical neuronal loss and depletion of mtDNA and complex I (CI). Patient NSCs showed mitochondrial dysfunction leading to ROS overproduction and downregulation of the NADH pathway. More importantly, the NAD+ precursor nicotinamide riboside (NR) significantly ameliorated mitochondrial defects in patient brain organoids. Our findings demonstrate that the iPSC model and brain organoids are good in vitro models of Alpers' disease; this first-in-its-kind stem cell platform for Alpers' syndrome enables therapeutic exploration and has identified NR as a viable drug candidate for Alpers' disease and, potentially, other mitochondrial diseases with similar causes.Peer reviewe
Consequence, signification and insolubles in fourteenth-century logic
Get PDFForty years ago, Niels Green-Pedersen listed five different accounts of valid consequence, variously promoted by logicians in the early fourteenth century and discussed by Niels Drukken of Denmark in his commentary on Aristotle's Prior Analytics, written in Paris in the late 1330s. Two of these arguably fail to give defining conditions: truth preservation was shown by Buridan and others to be neither necessary nor sufficient; incompatibility of the opposite of the conclusion with the premises is merely circular if incompatibility is analysed in terms of consequence. Buridan proposed to define consequence in terms of preservation of signifying as things are. John Mair pinpointed a sophism which threatens to undermine this proposal. Speaking anachronistically, Bradwardine turned it around: he suggested that a necessary condition on consequence was that the premises signify everything the conclusion signifies. Dumbleton gave counterexamples to Bradwardine's postulates in which the conclusion arguably signifies more than, or even completely differently from the premises. Yet a long-standing tradition held that some species of validity depend on the conclusion being in some way contained in the premises. We explore the connection between signification and consequence and its role in solving the insolubles.Peer reviewe
An international framework and local standardised test : a former item writer's autoethnography
Get PDFFunding: This article has been published in Open Access with the financial support of the University of St. Andrews Institutional Open Access Fund.A recent trend dominating education worldwide is the enactment of external accountability frameworks and standards-based assessment. Likewise, in language education, international standards like the Common European Framework of Reference (CEFR) have been increasingly used for local standardised test development and alignment. However, there has been little research into the application of the CEFR in item writing, the activity of creating new items and associated materials, in local standardised testing contexts. To bridge this gap, the current autoethnography shares my firsthand experience of writing items for a locally developed CEFR-aligned standardised English test in Vietnam. By combining evocative and analytic autoethnography, I aim to achieve two simultaneous aims. My first goal is to offer insight into a prevalent but not unproblematic practice of borrowing international standards to develop local high-stakes tests from the perspective of an item writer. Second, my item writing vignettes serve to demonstrate the advantages of autoethnography over other methodological approaches in investigating research contexts where access to suitable participants is particularly challenging.Peer reviewe
Family, identity and networking : European encounters in Polish female travel writing, 1770s-1820s
No full textBetween the 1770s and 1820s six elite women originating from the Poland’s magnateria traversed Europe. Their itineraries, at times carefully planned, other times highly improvised, followed established routes. Their experiences of visiting sites of artistic and historical importance, and interacting with foreign elites, were predictable. On the surface, their travels were like many others. However, investigating their private or semi-public travelogues and correspondence prove otherwise, exposing the unique character of each of these journeys and individuality of each of the travellers.
This thesis seeks to act as the first comprehensive study of manuscript travel writing by Polish women. It addresses three shortcomings in research into European travel, female travel, private and semi-public travel writing, and Polish women, bringing these research disciplines together. Firstly, it uncovers a large disregard for female travel accounts, especially where women are not presented as rare and rebellious individuals set against the backdrop of numerous male travellers, but rather as members of travelling groups, extending their agency in family and estate management into non-domestic settings. Secondly, this study addresses the shortage of research into manuscript source material, life-writing, which was intended for limited audiences or none at all, and which was therefore not intended for public readership by the authors. Thirdly, it exposes a predominant focus of current research on ‘Western’ European travel.
From finding emotional comfort after the deaths of children, to reconnecting with family, to planning honeymoons delayed by wars, to supervising children’s education, this thesis reveals the wealth of these women’s motivations for travelling and writing, as well as the variety of topics addressed by them throughout manuscript accounts – topics which were rarely discussed in travelogues shared with public readership. This study portrays them as uncensored, often overlooked, commentators of everyday experiences, expressing their thoughts, judgements and emotions in a fashion not seen in non-private accounts catering to readers’ expectations. Finally, it presents Polish history as European history, showcasing how integrated into European societies these Polish women were throughout their travels, and arguing against the concept of ‘Eastern Europe.
Recombinant production platform for Group A Streptococcus glycoconjugate vaccines
Get PDFFunding: The HCD laboratory is supported by Wellcome and Royal Society Grant 109357/Z/15/Z, the University of Dundee Wellcome Trust Funds 105606/Z/14/Z. The HCD and BWW laboratories are supported by Wellcome Innovator Award 221589/Z/20/Z and RIGHT Foundation grant RF-2023-V02. The GW laboratory was supported by grants from the Swedish Research Council (2022-03014) and the Knut and Alice Wallenberg Foundation. KA is supported by the Max Planck Society. HAS, FM are funded by Wellcome Innovator Award 221589/Z/20/Z, and independent research commissioned and funded by the NIHR Policy Research Programme (NIBSC Regulatory Science Research Unit).Group A Streptococcus (Strep A) is a human-exclusive bacterial pathogen killing annually more than 500,000 patients, and no current licensed vaccine exists. Strep A bacteria are highly diverse, but all produce an essential, abundant, and conserved surface carbohydrate, the Group A Carbohydrate, which contains a rhamnose polysaccharide (RhaPS) backbone. RhaPS is a validated universal vaccine candidate in a glycoconjugate prepared by chemical conjugation of the native carbohydrate to a carrier protein. We engineered the Group A Carbohydrate biosynthesis pathway to enable recombinant production using the industry standard route to couple RhaPS to selected carrier proteins within Escherichia coli cells. The structural integrity of the produced recombinant glycoconjugate vaccines was confirmed by Nuclear Magnetic Resonance (NMR) spectroscopy and mass spectrometry. Purified RhaPS glycoconjugates elicited carbohydrate-specific antibodies in mice and rabbits and bound to the surface of multiple Strep A strains of diverse M-types, confirming the recombinantly produced RhaPS glycoconjugates as valuable vaccine candidates.Peer reviewe
Curcuminoid derivatives with a donor-acceptor-donor architecture : an outstanding platform for highly-efficient near-infrared electroluminescence and amplified spontaneous emission
Get PDFFunding: This work was supported by Agence Nationale de la Recherche through the project Despot-Dyes (ANR-23-CE30-0003), through the framework of the French Investments for the Future Program Idex, UNISTRA (ANR-10-IDEX-0002) and SFRI STRAT'US project (ANR-20-SFRI-0012), financing the Interdisciplinary Thematic Institute HiFunMat (part of the ITI 2021–2028 of the UNISTRA, CNRS, and INSERM UMR 1121) and by Institut Carnot MICA. We also acknowledge JST CREST (grant no. JPMJCR22B3) and JSPS KAKENHI International Leading Research (ILR) (23K20039). Y.O. and D.V. acknowledge funding by the Fonds de la Recherche Scientifique-FNRS under Grant n°T.0226.24 (OMLED). Computational resources were also provided by the “‘Consortium des Équipements de Calcul Intensif”’ (CÉCI), funded by the “‘Fonds de la Recherche Scientifiques de Belgique”’ (FRS-FNRS) under Grant No. 2.5020.11. J.C.R. acknowledges the Engineering and Physical Sciences Research Council of the UK for the financial support from grant EP/Y021495/1.The development of high-efficiency near-infrared (NIR) emitters for organic light-emitting diodes (OLEDs) and organic semiconductor lasers has become an important target in organic photonics. Herein, it is demonstrated that donor-acceptor-donor borondifluoride curcuminoid derivatives represent a versatile and simple platform for the molecular engineering of high-efficiency NIR emitters combining thermally-activated delayed fluorescence (TADF) with excellent electroluminescence properties and amplified spontaneous emission (ASE) activity. A series of donor-acceptor-donor curcuminoid compounds containing triphenylamino-substituents for the donor side groups and various acceptor units in the meso position were designed and synthesized. The investigation of the effects of the molecular structure on the TADF properties show that the nature of the substituents enables a fine tuning of the emission wavelengths while maintaining high photoluminescence quantum yield values. These NIR TADF dyes were used in OLEDs with an external quantum efficiency of almost 1% for a maximum emission wavelength of 797 nm. They also show a low threshold tuneable amplified spontaneous emission between 725 and 900 nm. Overall, this study provides new essential insights to rationalize the TADF activity of this family of NIR emitters and offers important prospects for designing the next generation of NIR TADF-OLEDs and organic semiconductor laser materials.Peer reviewe
Mitigating bias in long-term terrestrial ecoacoustic studies
Get PDFFunding: This paper was developed at the second EcoHack workshop held at the University of Stirling in October 2023. The authors thank the workshop funders for their support: the Scottish Alliance for Geoscience, Environment and Society, the Company of Biologists (grant number B133), and the UK Acoustics Network (UKAN+, EPSRC grant number EP/V007866/1). D.J. was supported by a Leverhulme Trust Doctoral Studentship grant DS-2017-070 (Interdisciplinary Understanding for a Changing Arctic) and JSPF by a Leverhulme Trust early career fellowship (award reference ECF-2020-571).1. Long-term biodiversity monitoring is needed to track progress towards ambitious global targets to reduce species loss and restore ecosystems. The recent development of cheap and robust acoustic recording devices offers a cost-effective means of gathering standardised long-term datasets. 2. Accounting for sources of bias in ecological monitoring and research is a fundamental part of the study design process. To highlight this issue in the context of long-term terrestrial ecoacoustic monitoring, here we collate and discuss sources of bias arising from (i) hardware devices, (ii) firmware, software and analysis tools and (iii) the deployment environment. 3. One important source of bias is unavoidable changes in recording hardware—to demonstrate how this potentially introduces bias, we present two case studies comparing the output from simultaneous recordings from different recorders. 4. To mitigate biases, we recommend effective documentation of environmental and hardware-related variables, as well as a long-term data storage strategy that facilitates reanalysis. Additionally, the use of regular calibration tests to measure variation in the acoustic detection space will facilitate analytical approaches or post-hoc AI solutions that remove unwanted biases. 5. Synthesis and applications: The sources of bias and suggested mitigations described here will be of relevance to hardware manufacturers, ecological researchers and conservation practitioners. Researchers and conservation practitioners must be fully aware of relevant biases when designing long-term ecoacoustic studies and should incorporate appropriate mitigations into their study design.Peer reviewe
Non-visual crypsis : an updated review of current understanding
Get PDFRKM is grateful to the University of St Andrews and the Perry Foundation for funding.Crypsis, a form of camouflage wherein an organism conceals itself by hindering initial detection by a receiver, is widespread in the animal kingdom. Though crypsis has been the focus of much research, discussions of its function and evolution are mostly restricted to the visual domain. Crypsis is nevertheless a concept that can be usefully applied to non-visual sensory perception; and indeed, there have been major developments in the field of non-visual crypsis in the past decade. In this review, we first offer a definition of crypsis– one not restricted to the visual senses– before critically considering current avenues of study into non-visual crypsis and highlighting key, up-to-date findings. We examine which non-visual senses have the most convincing examples of crypsis, finding that auditory and olfactory crypsis have the most support, but this may be due to greater research efforts towards these senses rather than a natural dearth of examples in other senses. We also discuss the possibility of crypsis in underexplored senses, including mechanoreception, heat sensing, and touch. For all non-visual senses, we see great opportunities for future theoretical and empirical studies to explore the mechanism, ecological impact, and evolutionary and co-evolutionary implications of cryptic adaptations. We hope this review will provide an informative base for researchers, and encourage a shift away from restrictive, vision-centric definitions of crypsis.Peer reviewe
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