Numerical modelling of MPA-CVD reactors with the discontinuous Galerkin finite element method

In this article we develop a fully self consistent mathematical model describing the formation of a hydrogen plasma in a microwave power assisted chemical vapour deposition (MPA-CVD) reactor employed for the manufacture of synthetic diamond. The underlying multi-physics model includes constituent equations for the background gas mass average velocity, gas temperature, electromagnetic field energy and plasma density. The proposed mathematical model is numerically approximated based on exploiting the discontinuous Galerkin finite element method. We demonstrate the practical performance of this computational approach on a variety of CVD reactor geometries for a range of operating conditions

Declining home range area predicts reduced late-life survival in two wild ungulate populations

Demographic senescence is increasingly recognised as an important force shaping the dynamics of wild vertebrate populations. However, our understanding of the processes that underpin these declines in survival and fertility in old age remains limited. Evidence for age‐related changes in foraging behaviour and habitat use is emerging from wild vertebrate studies, but the extent to which these are driven by within‐individual changes, and the consequences for fitness, remain unclear. Using longitudinal census observations collected over four decades from two long‐term individual‐based studies of unmanaged ungulates, we demonstrate consistent within‐individual declines in home range area with age in adult females. In both systems, we found that within‐individual decreases in home range area were associated with increased risk of mortality the following year. Our results provide the first evidence from the wild that age‐related changes in space use are predictive of adult mortality

British and Irish newspapers implicitly support single-use masks over reusable face coverings

The environmental impact of waste caused by single-use masks or face coverings is an under-considered effect associated with the COVID-19 pandemic. Our study demonstrates how the discourse in British and Irish newspapers in the March 2020-December 2021 time frame relates to this problem. The combination of the protective purpose of face masks and their potential environmental impacts through littering or waste management means the wearing of face masks is simultaneously associated with the health crisis and creation of a new environmental challenge, combining two strands of journalism. By a combination of quantitative and qualitative discourse analysis, we identify concepts commonly associated with the terms "face-covering" and "mask", particularly concerning whether they refer to a disposable or reusable item. Results suggest that the newspaper discourse generally favoured references to single-use surgical masks. Newspapers reported on the environmental impact of face masks only in very limited ways. We propose that the increase in waste caused by face masks can be related to prevailing representations of single-use surgical masks and limited attention paid to environmental concerns

Determining the impact of gold nanoparticles on amyloid aggregation with 2D IR spectroscopy

As nanomaterials become more prevalent in both industry and medicine, it is crucial to fully understand their health risks. One area of concern is the interaction of nanoparticles with proteins, including their ability to modulate the uncontrolled aggregation of amyloid proteins associated with diseases such as Alzheimer’s and type II diabetes and potentially extend the lifetime of cytotoxic soluble oligomers. This work demonstrates, for this first time, that two-dimensional infrared spectroscopy and 13C18O isotope labeling can be used to follow the aggregation of human islet amyloid polypeptide (hIAPP) in the presence of gold nanoparticles (AuNPs) with single-residue structural resolution. 60 nm AuNPs were found to inhibit hIAPP, tripling the aggregation time. Furthermore, calculating the actual transition dipole strength of the backbone amide I’ mode reveals that hIAPP forms a more ordered aggregate structure in the presence of AuNPs. Ultimately, such studies can provide insight into how mechanisms of amyloid aggregation are altered in the presence of nanoparticles, furthering our understanding of protein-nanoparticle interactions