Phase Transitions in Binary and Ternary Vanadium Oxides: Implications for Thermochromic and Intercalation Batteries

The implications of climate change and resource scarcity stand to impose great strain on society, and require the development of novel ways to conserve and store energy. Due to the large portion of energy use accounted for the heating and cooling of buildings worldwide, thermochromic coatings offer promise for reducing energy footprints. Vanadium dioxide has long been a material of interest because of the intrinsitc metalinsulator transition wherein the material switches between a low-temperature, insulating, monoclinic phase (EB = 0.6 eV, infrared transparent) and a high temperature, metallic, tetragonal phase (infrared reflective). In this work we present the development of a scalable synthesis of extremely high quality vanadium dioxide nanoparticles, exhibiting superior a superior metal-insulator transition comparable to the highest quality films produced via molecular beam epitaxy. In the field of energy storage, high energy and power density batteries are imperative to help drive the electrification of the transportation industry as well as for grid-level storage. However, there are many issues with current state-of-the-art Li-ion battery technologies including high cost, poor high rate performance, and safety concerns that hinder large scale adoption. However, the mechanisms governing cation transport and phase formation in battery host materials are not well understood. The study of these mechanisms is further complicated by their non-equilibrium nature, requiring multiple modes of characterization that combine theoretical calculations with geometric and electronic structure determination across multiple length scales. In this work, we have used chemical lithiation as a Li-ion insertion tool to study the mechanism of lithium insertion and diffusion through substrate free nanowires and nanoplatelets of vanadium pentoxide. Specifically, we have examined the dependence of these properties on particle size. Systematic studies utilizing X-ray diffraction, Raman spectroscopy, X-ray absorption spectroscopy, and scanning transmission X-ray microscopy have allowed us to identify the formation of two-phase mixtures upon Li-ion insertion. Combining these measurements with first principles calculations has allowed us to determine the mechanistic origins of this phase separation, and suggest that the barrier to diffusion of Li-ions through layered vanadium pentoxide arises from the formation of a small polaron upon Li-ion insertion. Understanding the mechanisms by which lithium mobility through the layered vanadium pentoxide structure is impeded has allowed us to develop a novel polymorph of vanadium pentoxide that minimizes the strength of the polaronic confinement. By replacing the layered framework with one-dimensional tunnels that provide a more rigid framework and spread the localized electron, we have achieved facile, fast, single-phase lithium insertion and removal

Habitat change and restoration: Responses of a forest-floor mammal species to manipulations of fallen timber in floodplain forests

In forests and woodlands, fallen timber (logs and large branches) is an important habitat element for many species of animals. Fallen timber has been systematically stripped in many forests, eliminating an important structural element. This study describes results of a ‘meso-scale’ experiment in which fallen timber was manipulated in a floodplain forest of the Murray River in south-eastern Australia. A thousand tons of wood were redistributed after one-year’s pre-manipulation monitoring, while a further two-year’s post-manipulation monitoring was conducted. The response of the main forest-floor small-mammal species, the Yellow-footed Antechinus Antechinus flavipes, to alterations of fallen-wood loads is documented. Results of the experiment will help to frame guidelines for fallen-timber management in these extensive floodplain forests

Proliferation of metallic domains caused by inhomogeneous heating near the electrically-driven transition in VO2_2 nanobeams

We discuss the mechanisms behind the electrically driven insulator-metal transition in single crystalline VO$_2$ nanobeams. Our DC and AC transport measurements and the versatile harmonic analysis method employed show that non-uniform Joule heating causes phase inhomogeneities to develop within the nanobeam and is responsible for driving the transition in VO$_{2}$. A Poole-Frenkel like purely electric field induced transition is found to be absent and the role of percolation near and away from the electrically driven transition in VO$_{2}$ is also identified. The results and the harmonic analysis can be generalized to many strongly correlated materials that exhibit electrically driven transitions

Responses of floodplain birds to high-amplitude precipitation fluctuations over two decades

Globally, high-amplitude variation in weather (e.g. precipitation) is increasing in frequency and magnitude. This appears to be so for the southern Murray-Darling Basin, Australia, where droughts of unprecedented (in the instrumental record, extending back to the mid-1800s) depth and duration (1997–first half of 2010; second half of 2012–) are being punctuated by extreme wet periods, albeit of shorter duration (‘Big Wet’, second half of 2010–first half of 2012). We have previously reported on the responses of floodplain-forest birds to the cessation of the longest recorded drought (‘Big Dry’, 1997–first half of 2010), but we found little evidence of a rebound, at least shortly after the Big Wet. However, we reasoned that there may have been insufficient time for the birds to have responded in that short time, so we repeated the survey program 5 years after the end of the Big Wet (2017). Bird occurrences, reproductive activity and success were substantially greater compared with late in the Big Dry (2009) than they had been soon after the Big Wet (2013). However, bird occurrences still fell well below measurements in the early-Big Dry (1998), so that the avifauna appears to be in decline, most probably because the length of drought periods far exceeds that of wet periods giving the birds too little time to recover fully. © 2022 The Authors. Austral Ecology published by John Wiley & Sons Australia, Ltd on behalf of Ecological Society of Australia

pTDP-43 aggregates accumulate in non-central nervous system tissues prior to symptom onset in amyotrophic lateral sclerosis : a case series linking archival surgical biopsies with clinical phenotypic data

Acknowledgements The authors would like to thank the staff at the NHS Lothian BioResource (Vishad Patel and Craig Marshall) and the NHS Grampian biorepository (Joan Wilson) and the staff and corefunded resources of the imaging and histology core facility at the Institute of Medical Sciences (Gillian Milne, Lucinda Wight, and Debbie Wilkinson). This study was funded by the Pathological Society/Jean Shanks Foundation (JSPS CLSG 202002 to JMG and JO’S), The Royal Society (RGS\R1\221396 to JMG) and the Wellcome Trust (108890/Z/15/Z to OR). Funders had no role in study design, data collection, data analyses, interpretation, or writing the manuscriptPeer reviewedPostprin

RNA aptamer reveals nuclear TDP-43 pathology is an early aggregation event that coincides with STMN-2 cryptic splicing and precedes clinical manifestation in ALS

Open Access via the Springer Agreement The research leading to this manuscript has been supported by (i) a Target ALS foundation grant to JMG, MHH, GGT, EZ and NS and employing MG and FMW BB-2022-C4-L2; (ii) an NIH grant to JG and MHH, employing HS and FR R01NS127186; (iii) the European Research Council (RIBOMYLOME_309545 and ASTRA_855923) to GGT; and (iv) an MND Association Lady Edith Wolfson Junior Non-Clinical Fellowship to RS Saleeb/Oct22/980-799 (RSS). The authors would also like to thank the University of Aberdeen Microscopy and Histology Core Facility in the Institute of Medical Sciences.Peer reviewe

Managing lifestyle change to reduce coronary risk: a synthesis of qualitative research on peoples’ experiences

Background Coronary heart disease is an incurable condition. The only approach known to slow its progression is healthy lifestyle change and concordance with cardio-protective medicines. Few people fully succeed in these daily activities so potential health improvements are not fully realised. Little is known about peoples’ experiences of managing lifestyle change. The aim of this study was to synthesise qualitative research to explain how participants make lifestyle change after a cardiac event and explore this within the wider illness experience. Methods A qualitative synthesis was conducted drawing upon the principles of meta-ethnography. Qualitative studies were identified through a systematic search of 7 databases using explicit criteria. Key concepts were identified and translated across studies. Findings were discussed and diagrammed during a series of audiotaped meetings. Results The final synthesis is grounded in findings from 27 studies, with over 500 participants (56% male) across 8 countries. All participants experienced a change in their self-identity from what was ‘familiar’ to ‘unfamiliar’. The transition process involved ‘finding new limits and a life worth living’ , ‘finding support for self’ and ‘finding a new normal’. Analyses of these concepts led to the generation of a third order construct, namely an ongoing process of ‘reassessing past, present and future lives’ as participants considered their changed identity. Participants experienced a strong urge to get back to ‘normal’. Support from family and friends could enable or constrain life change and lifestyle changes. Lifestyle change was but one small part of a wider ‘life’ change that occurred. Conclusions The final synthesis presents an interpretation, not evident in the primary studies, of a person-centred model to explain how lifestyle change is situated within ‘wider’ life changes. The magnitude of individual responses to a changed health status varied. Participants experienced distress as their notion of self identity shifted and emotions that reflected the various stages of the grief process were evident in participants’ accounts. The process of self-managing lifestyle took place through experiential learning; the level of engagement with lifestyle change reflected an individual’s unique view of the balance needed to manage ‘realistic change’ whilst leading to a life that was perceived as ‘worth living’. Findings highlight the importance of providing person centred care that aligns with both psychological and physical dimensions of recovery which are inextricably linked

RNA aptamer reveals nuclear TDP-43 pathology is an early aggregation event that coincides with STMN-2 cryptic splicing and precedes clinical manifestation in ALS

TDP-43 is an aggregation-prone protein which accumulates in the hallmark pathological inclusions of amyotrophic lateral sclerosis (ALS). However, the analysis of deeply phenotyped human post-mortem samples has shown that TDP-43 aggregation, revealed by standard antibody methods, correlates poorly with symptom manifestation. Recent identification of cryptic-splicing events, such as the detection of Stathmin-2 (STMN-2) cryptic exons, are providing evidence implicating TDP-43 loss-of-function as a potential driving pathomechanism but the temporal nature of TDP-43 loss and its relation to the disease process and clinical phenotype is not known. To address these outstanding questions, we used a novel RNA aptamer, TDP-43APT, to detect TDP-43 pathology and used single molecule in situ hybridization to sensitively reveal TDP-43 loss-of-function and applied these in a deeply phenotyped human post-mortem tissue cohort. We demonstrate that TDP-43APT identifies pathological TDP-43, detecting aggregation events that cannot be detected by classical antibody stains. We show that nuclear TDP-43 pathology is an early event, occurring prior to cytoplasmic accumulation and is associated with loss-of-function measured by coincident STMN-2 cryptic splicing pathology. Crucially, we show that these pathological features of TDP-43 loss-of-function precede the clinical inflection point and are not required for region specific clinical manifestation. Furthermore, we demonstrate that gain-of-function in the form of extensive cytoplasmic accumulation, but not loss-of-function, is the primary molecular correlate of clinical manifestation. Taken together, our findings demonstrate implications for early diagnostics as the presence of STMN-2 cryptic exons and early TDP-43 aggregation events could be detected prior to symptom onset, holding promise for early intervention in ALS

Origin of the Spin-Orbital Liquid State in a Nearly J=0 Iridate Ba3ZnIr2O9

We show using detailed magnetic and thermodynamic studies and theoretical calculations that the ground state of Ba3ZnIr2O9 is a realization of a novel spin-orbital liquid state. Our results reveal that Ba3ZnIr2O9 with Ir5+ (5d(4)) ions and strong spin-orbit coupling (SOC) arrives very close to the elusive J = 0 state but each Ir ion still possesses a weak moment. Ab initio density functional calculations indicate that this moment is developed due to superexchange, mediated by a strong intradimer hopping mechanism. While the Ir spins within the structural Ir2O9 dimer are expected to form a spin-orbit singlet state (SOS) with no resultant moment, substantial frustration arising from interdimer exchange interactions induce quantum fluctuations in these possible SOS states favoring a spin-orbital liquid phase down to at least 100 mK