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Are long-horizon expectations (de-)stabilizing? Theory and experiments
Get PDFFunding: This research has been partly financed by the EU FP7 project MACFINROBODS, grant agreement no. 612796. Isabelle Salle is grateful to the International Network on Expectational Coordination, funded by the Institute for New Economic Thinking, for financing her stay at the University of Oregon during spring 2016.The impact of finite forecasting horizons on price dynamics is examined in a standard infinite-horizon asset-pricing model. Our theoretical results link forecasting horizon inversely to expectational feedback, and predict a positive relationship between expectational feedback and various measures of asset-price volatility. We design a laboratory experiment to test these predictions. Consistent with our theory, short-horizon markets are prone to substantial and prolonged deviations from rational expectations, whereas markets with even a modest share of long-horizon forecasters exhibit convergence. Longer-horizon forecasts display more heterogeneity but also prevent coordination on incorrect anchors – a pattern that leads to mispricing in short-horizon markets.Peer reviewe
Halogenated adenine and adenosine natural products in Streptomyces sp. JCM9888
Get PDFFunding: The authors thank the EPSRC and the Leverhulme Trusts for financial support. The Chinese Scholarship Council is also acknowledged for studentship support (Y.C.).Ascamycin 1 and dealanylascamycin 2 are adenosine containing nucleoside antibiotics carrying the rare 5’-O-sulfamoyl ribose motif and a chlorine atom attached to C2 of the adenine ring. Gene knockouts (ΔacmK and ΔacmJ) in the producing strain, Streptomyces sp. JCM9888, generated mutants that were disabled in the assembly of the sulfamoyl moiety. This resulted in the production of 2-chloroadenosine 3 and 2-chloroadenine 4, indicating that purine halogenation can occur independently of sulfamoylation. Incubations in media enriched in bromide content resulted also in the identification of 2-bromoadenine 5, 2-bromoadenosine 6 and 5′-O-sulfamoyl-2-bromoadenosine 7.Peer reviewe
Pearl sac gene expression profiles associated with pearl attributes in the silver-lip pearl oyster, Pinctada maxima
Get PDFFunding: This research was funded by an Australian Research Council Linkage Grants LP0990280 and LP130100086 to BD and PM.Pearls are highly prized biomineralized gemstones produced by molluscs. The appearance and mineralogy of cultured pearls can vary markedly, greatly affecting their commercial value. To begin to understand the role of pearl sacs-organs that form in host oysters from explanted mantle tissues that surround and synthesize pearls-we undertook transcriptomic analyses to identify genes that are differentially expressed in sacs producing pearls with different surface and structural characteristics. Our results indicate that gene expression profiles correlate with different pearl defects, suggesting that gene regulation in the pearl sac contributes to pearl appearance and quality. For instance, pearl sacs that produced pearls with surface non-lustrous calcification significantly down-regulate genes associated with cilia and microtubule function compared to pearl sacs giving rise to lustrous pearls. These results suggest that gene expression profiling can advance our understanding of processes that control biomineralization, which may be of direct value to the pearl industry, particularly in relation to defects that result in low value pearls.Peer reviewe
On tin and lithium granite systems : a crustal evolution perspective
Get PDFFunding: NJG and MM thank the Leverhulme Trust for support (Research Project Grant RPG-2023-210). LK was supported by a National Environmental Research Council PhD studentship (Grant no. NE/S007474/1).The battery metals tin and lithium (Sn–Li) are key to renewable energy technologies, with demand driving new interest in the formation and exploration of tin granites and lithium-caesium‑tantalum (LCT) pegmatites. These magmatic-hydrothermal systems originate from highly evolved, reduced, peraluminous, volatile-rich granitic melts which develop elevated concentrations of incompatible metals. Tin granite deposits form either as disseminated magmatic cassiterite, or hydrothermal quartz-cassiterite lodes and greisens, with Li-bearing fluids driving late-stage mica alteration to Li-rich varieties. Conversely, LCT pegmatites record a complex crystallization with Li ores forming during primary magmatic crystallization, and Sn associated with hydrothermal overprints. The first appearance in the geological record of Snsingle bondLi granites and pegmatites is linked to the global onset of crustal reworking during Neoarchean terrane assembly, highlighting the key role of crustal evolution processes in their formation. In this contribution, we review our current understanding of Sn–Li metallogeny from source to sink through the lens of crustal processes. We focus on recent advances in petrological modelling and in situ microanalysis of rock-forming and accessory minerals, to examine tin granite and LCT pegmatite formation from partial melting of a source rock through melt extraction, emplacement and fractionation, to late-stage hydrothermal processes. Quantitative thermodynamic modelling of crustal melting brings the ability to explore source rocks and resulting melt compositions under various P-T conditions. Melt Sn–Li concentrations are controlled by mineral breakdown and metal partitioning between restite and melt. Sn and Li are primarily hosted in muscovite and biotite; deep crustal melting driving biotite breakdown releases Sn and Li into the melt, however shallow muscovite-driven melting restricts melt Li enrichment. It is difficult to generate a melt capable of saturating Li ore minerals from melting an ordinary clay protolith, hence either multi-stage melting or source metal pre-enrichment may be required. Microanalysis allows high-precision geochemical and isotopic characterization of mineral phases. We review and summarize case studies using accessory minerals such as zircon and apatite, whose compositions are particularly powerful in tracking metal concentration and mobility during magma evolution and the magmatic-hydrothermal transition, with potential applications to exploration efforts. In tandem, the development of novel geochronometers such as cassiterite or columbite U–Pb help improve constraints of the age and timing of mineralization with respect to magmatism. Finally, we consider the formation of tin granites and LCT pegmatites in 4D using the framework of long-lived, transcrustal magmatic systems. These models may help describe how prolonged melt generation, extraction, and evolution over protracted timescales allows progressive enrichment of Sn and Li. Combined, such efforts can help answer open questions on the formation of Snsingle bondLi granite systems, to build improved 4D mineral systems models and inform fresh approaches to prospect for new deposits.Peer reviewe
Introducing fair work through ‘soft’ regulation in outsourced public service networks : explaining unintended outcomes in the implementation of the Scottish Living Wage policy
Get PDFFunding: Authors would like to thank the Coalition of Care and Support Providers Scotland CCPS for funding this project.Using a regulatory analysis from Martinez Lucio and Mackenzie (2014 and 2016), this study contributes to debates concerning the capacity of ‘soft’ regulation to advance employment conditions and outcomes. This study explores the implementation of a real living wage policy for employees in outsourced Scottish social care. Despite employer compliance in implementing the living wage, it had a mixed impact on the income of workers and did not improve staff recruitment and retention. The theoretical framework challenges recent optimistic views concerning the impact of such regulation by revealing unintended and problematic consequences, such as problems with differentials and providers walking away from contracts. It further reveals how actor roles, interests, power resources and inter-relationships, as well as surrounding structural contextual influences (austerity, marketisation and engrained values and processes in political settlements), interacted to shape these outcomes. Insights from this study include that ‘soft’ regulation was unable to create conditions for actors such as trade unions, employers and non-governmental organisations to colonise or seize the regulatory space to secure the full benefits of the Scottish Living Wage. The political settlement with the Scottish Government allowed local authorities to retain coercive control over other actors in the regulatory space. Employers and trade unions were further hindered by lack of unity and continued isolation from decisions, respectively. Surrounding economic and ideological restrictions imposed by the central UK government’s austerity agenda, and the retention of powers over employment regulation added to the failure of these ‘soft’ measures to increase pay and improve recruitment and retention in social care.Peer reviewe
NaLiFe(C2O4)2 : a polyanionic Li/Na-ion battery cathode exhibiting cationic and anionic redox
Get PDFFunding: The authors would like to thank the Faraday Institution NEXGENNA project (FIRG018) and EPSRC EP/R030472/1 for financial support. AGM wishes to thank the Faraday Institution for financial support and training (Grant number FITG033). The authors are also thankful to EPSRC Light Element Analysis Facility Grant EP/T019298/1 and the EPSRC Strategic Equipment Resource Grant EP/R023751/1. They are grateful to the UK Materials and Molecular Modelling Hub for computational resources, which is partially funded by EPSRC (EP/P020194/1).Recently, polyanionic compounds have received great interest as alternative cathode materials to conventional oxides due to their different advantages in cost, safety, structural stability, as well as being environmentally friendly. However, the vast majority of polyanionic materials reported so far rely exclusively upon the redox reaction of the transition metal for lithium/sodium transfer. The development of multielectron redox-active cathode materials is a top priority for achieving high energy density with long cycle life in the next-generation secondary battery applications. Triggering anion redox activity is a promising strategy to enhance the energy density of polyanionic cathode materials for Li/Na-ion batteries. In addition to transition metal redox activity, the oxalate group also shows redox behavior enabling reversible charge/discharge and high capacity without gas evolution. Herein, we report NaLiFe(C2O4)2 as a new positive electrode and use different characterization techniques such as Raman spectroscopy and Mössbauer analyses to characterise this dual-ion redox process experimentally. First-principles calculations also help to understand the interactions between the transition metal and the oxalate group as the main factor that modulates the cationic and polyanionic redox couples in these materials.Peer reviewe
Towards the industrial implementation of Mn-based catalyst for the hydrogenation of ketones and carboxylic esters
Get PDFThere is a constant pressure in industry to move away from platinum group metals (PGM) and achieve more environmentally friendly and sustainable production processes in the future. Recently developed Mn-based catalysts offer an interesting opportunity to complement established catalysts based on Ru. In this article, recent achievements in the field are highlighted and recent achievements in the collaboration of Solvias AG with the group of Prof. M. Clarke towards the implementation of these catalysts on industrial scale are outlined.Peer reviewe
The effect of lightning on the atmospheric chemistry of exoplanets and potential biosignatures
Get PDFContext. Lightning has been suggested to play a role in triggering the occurrence of bio-ready chemical species. Future missions such as PLATO, ARIEL, HWO, and LIFE, as well as ground-based extremely large telescopes (ELTs), will carry out investigations of the atmospheres of potentially habitable exoplanets. Aims. We aim to study the effect of lightning on the atmospheric chemistry. We also consider how it affects false-positive and false-negative biosignatures and whether these effects would be observable on exo-Earth and TRAPPIST-1 planets. Methods. We utilised a combination of laboratory experiments and photochemical and radiative transfer modelling. We conducted spark discharge experiments in N2−CO2−H2 gas mixtures, representing a range of possible rocky-planet atmospheres. We investigated the production of potential lightning signatures (CO and NO), possible biosignature gases (N2O, NH3, and CH4), and important prebiotic precursors (HCN and urea). Using the measured CO and NO production rates, we conducted photochemical simulations for oxygen-rich and anoxic atmospheres for rocky planets orbiting in the habitable zones of the Sun and TRAPPIST-1 for a range of lightning flash rates. Synthetic spectra were calculated using SMART to study the atmosphere’s reflectance, along with the emission and transmission spectra. Results. Lightning enhances the spectral features of NO, NO2, and (in some cases) CO through direct production; whereas CH4 and C2H6 may be enhanced indirectly. Lightning at a flash rate slightly higher than on modern-day Earth is able to mask the ozone features of an oxygen-rich, biotic atmosphere, making it harder to detect the biosphere of such a planet. Similarly, lightning at a flash rate at least ten times higher than on modern-day Earth is also able to mask the presence of ozone in the anoxic, abiotic atmosphere of a planet orbiting a late M dwarf, reducing the potential for a false-positive life detection. Conclusions. The threshold lightning flash rates to eliminate oxygen (>0.1%) and ozone false positive biosignatures on planets orbiting ultra-cool dwarfs is up to ten times higher than the modern flash rate. This result indicates that lightning cannot always prevent these false-positive scenarios.Peer reviewe
My litel suffisaunce : humility and its compatriots in Middle English literature
Get PDFTropes of humility are as ubiquitous in the literature of Medieval Europe as they are understudied in the modern academic literature. While many individual examples are dealt with frequently, a comprehensive investigation of them in the vernacular of Later Medieval England does not yet exist. This study aims to provide that.
Tropes of humility in this period are varied and polyphonic, a single, clear assertion of their function is impossible. Nor are clear categories easily drawn, as the formal varieties and rhetorical styles of these tropes blend smoothly into each other. Instead of attempting to provide either of these things, this study provides a broad survey of functions which these tropes served. In particular, this study is concerned with the ways authors used tropes of humility to engage with, navigate, and express notions of authority, authorship, and power.
Broadly speaking, tropes of humility served as a flexible and powerful tool throughout the Later Middle Ages for dealing with the complex power structures authors found themselves in. Though they took repetitive forms, these forms should not be seen as a lack of though or creativity. Instead, they should be understood as medieval authors themselves understood them: As set texts to be modified and deployed thoughtfully and creatively, to achieve one’s particular ends in specific circumstances
The oil and gas geologist’s Arctic in the age of the Anthropocene : knowledge, politics and imaginative geologies
Get PDFThis dissertation is about how geologists produce Arctic oil and gas estimate knowledge and think about what they do at a time of profound environmental and climate change (often dubbed the Anthropocene). Accordingly, the study considers how geological knowledge is produced, for what purpose and with what effects, and how geologists, chiefly in government but also in academia and industry, see themselves and their role in changing energy landscapes. Geologists are much neglected agents in contemporary energy and climate dynamics and yet are crucial to how the present and future are envisioned and represented. The originality of the study lies in its attempt to probe the geological data on Arctic oil and gas estimation and develop an insider-outsider approach to engaging with geologists that is based on a close textual examination of 23 semi-structured interviews (from a larger total of 42 conducted for the study). This involved the investigator working (‘shuttling’) between geological and geographical knowledges and approaches – trained as an industrial geologist and seeking to develop critical geographical perspectives. The thesis draws three main recognitions from the documentary and interview data, namely that: 1. Arctic oil and gas geologists perceive today as a time of unsettling change (a ‘whiplash’) and thus that their knowledge is inherently political; 2. Arctic oil and gas geologists are a much understudied and underestimated group in the story of how and why lines between Arctic ‘fossil fuel’ geologists and Arctic ‘clean energy’ geologists are becoming blurred in shifting energy landscapes (a ‘swivel’ is underway); and 3. studies like this one can add something to current debates about the power and future of oil and gas by showing the need for new interdisciplinary conversations with Arctic geologists. Finally, the thesis reflects on the student’s personal journey in translating between the worlds of geology and geography."This work was supported by the Robertson Scholarship; and the Research Institute for Sustainability Helmholz Centre Potsdam."--Fundin
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