Carbon Capture and Storage (CCS) pipeline operating temperature effects on UK soils: The first empirical data

This paper presents the first empirical data of soil temperature and soil moisture profiles with depth in the context of a buried Carbon Capture and Storage transportation pipeline operating at higher than ambient soil temperatures. In an experimental approach, soil temperature responses are non-linear and are raised and restricted to within 45 cm of the subsurface heat source (hypothetical pipeline). A surface heat source is included to investigate interactions of natural seasonal surface heating of soils with subsurface heat. There is no interaction between subsurface and surface heat sources in the experimental system. Soil moisture profiles vary with soil type, with overall soil moisture losses of >10% over experimental time courses. Modelled soil temperature profiles show that the ability of soils to buffer thermal movement from depths up to 1.2 m from the surface is currently inadequately represented. Measurements provide the first elementary data of soil temperature changes resulting from a subsurface heat source for more accurate modelling of soil/pipeline interactions

The regulation of plant secondary metabolism in response to abiotic stress : interactions between heat shock and elevated CO2

Future climate change is set to have an impact on the physiological performance of global vegetation. Increasing temperature and atmospheric CO2 concentration will affect plant growth, net primary productivity, photosynthetic capability, and other biochemical functions that are essential for normal metabolic function. Alongside the primary metabolic function effects of plant growth and development, the effect of stress on plant secondary metabolism from both biotic and abiotic sources will be impacted by changes in future climate. Using an untargeted metabolomic fingerprinting approach alongside emissions measurements, we investigate for the first time how elevated atmospheric CO2 and temperature both independently and interactively impact on plant secondary metabolism through resource allocation, with a resulting “trade-off” between secondary metabolic processes in Salix spp. and in particular, isoprene biosynthesis. Although it has been previously reported that isoprene is suppressed in times of elevated CO2, and that isoprene emissions increase as a response to short-term heat shock, no study has investigated the interactive effects at the metabolic level. We have demonstrated that at a metabolic level isoprene is still being produced during periods of both elevated CO2 and temperature, and that ultimately temperature has the greater effect. With global temperature and atmospheric CO2 concentrations rising as a result of anthropogenic activity, it is imperative to understand the interactions between atmospheric processes and global vegetation, especially given that global isoprene emissions have the potential to contribute to atmospheric warming mitigation

Rational design of a polyurethane foam

Polyurethane (PU) foams are exceptionally versatile due to the nature of PU bond formation and the large variety of polymeric backbones and formulation components such as catalysts and surfactants. This versatility introduces a challenge, namely a near unlimited number of variables for formulating foams. In addition to this, PU foam development requires expert knowledge, not only in polyurethane chemistry but also in the art of evaluating the resulting foams. In this work, we demonstrate that a rational experimental design framework in conjunction with a design of experiments (DoE) approach reduces both the number of experiments required to understand the formulation space and reduces the need for tacit knowledge from a PU expert. We focus on an in-depth example where a catalyst and two surfactants of a known formulation are set as factors and foam physical properties are set as responses. An iterative DoE approach is used to generate a set of foams with substantially different cell morphology and hydrodynamic behaviour. We demonstrate that with 23 screening formulations and 16 final formulations, foam physical properties can be modelled from catalyst and surfactant loadings. This approach also allows for the exploration of relationships between the cell morphology of PU foam and its hydrodynamic behaviour

The Role of Radioactivities in Astrophysics

I present both a history of radioactivity in astrophysics and an introduction to the major applications of radioactive abundances to astronomy

Latent anti-nutrients and unintentional breeding consequences in Australian Sorghum bicolor varieties

Modern feed quality sorghum grain has been bred to reduce anti-nutrients, most conspicuously condensed tannins, but its inclusion in the diets of monogastric animals can still result in variable performance that is only partially understood. Sorghum grain contains several negative intrinsic factors, including non-tannin phenolics and polyphenols, phytate, and kafirin protein, which may be responsible for these muted feed performances. To better understand the non-tannin phenolic and polyphenolic metabolites that may have negative effects on nutritional parameters, the chemical composition of sorghum grain polyphenol extracts from three commercial varieties (MR-Buster, Cracka, and Liberty) was determined through the use of an under-studied, alternative analytical approach involving Fourier-transform infrared (FT-IR) spectroscopy and direct ionization mass spectrometry. Supervised analyses and interrogation of the data contributing to variation resulted in the identification of a variety of metabolites, including established polyphenols, lignin-like anti-nutrients, and complex sugars, as well as high levels of fatty acids which could contribute to nutritional variation and underperformance in monogastrics. FT-IR and mass spectrometry could both discriminate among the different sorghum varieties indicating that FT-IR, rather than more sophisticated chromatographic and mass spectrometric methods, could be incorporated into quality control applications

2-C-methylated nucleotides terminate virus RNA synthesis by preventing active site closure of the viral RNA-dependent RNA polymerase

The 2-C-methyl ribonucleosides are nucleoside analogs representing an important class of antiviral agents, especially against positive-strand RNA viruses. Their value is highlighted by the highly successful anti-hepatitis C drug sofosbuvir. When appropriately phosphorylated, these nucleotides are successfully incorporated into RNA by the virally encoded RNA-dependent RNA polymerase (RdRp). This activity prevents further RNA extension, but the mechanism is poorly characterized. Previously, we had identified NMR signatures characteristic of formation of RdRp-RNA binary and RdRp-RNA-NTP ternary complexes for the poliovirus RdRp, including an open-to-closed conformational change necessary to prepare the active site for catalysis of phosphoryl transfer. Here we used these observations as a framework for interpreting the effects of 2-C-methyl adenosine analogs on RNA chain extension in solution-state NMR spectroscopy experiments, enabling us to gain additional mechanistic insights into 2-C-methyl ribonucleoside-mediated RNA chain termination. Contrary to what has been proposed previously, poliovirus RdRp that was bound to RNA with an incorporated 2-C-methyl nucleotide could still bind to the next incoming NTP. Our results also indicated that incorporation of the 2-C-methyl nucleotide does not disrupt RdRp-RNA interactions and does not prevent translocation. Instead, incorporation of the 2-C-methyl nucleotide blocked closure of the RdRp active site upon binding of the next correct incoming NTP, which prevented further nucleotide addition. We propose that other nucleotide analogs that act as nonobligate chain terminators may operate through a similar mechanism

The role of exploitation in the establishment of mutualistic microbial symbioses

Evolutionary theory suggests that the conditions required for the establishment of mutualistic symbioses through mutualism alone are highly restrictive, often requiring the evolution of complex stabilising mechanisms. Exploitation, whereby initially the host benefits at the expense of its symbiotic partner and mutual benefits evolve subsequently through trade-offs, offers an arguably simpler route to the establishment of mutualistic symbiosis. In this review, we discuss the theoretical and experimental evidence supporting a role for host exploitation in the establishment and evolution of mutualistic microbial symbioses, including data from both extant and experimentally evolved symbioses. We conclude that exploitation rather than mutualism may often explain the origin of mutualistic microbial symbioses

Comparison of independent evolutionary origins reveals both convergence and divergence in the metabolic mechanisms of symbiosis

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record Through the merger of previously independent lineages, symbiosis promotes the acquisition of new traits and exploitation of inaccessible ecological niches [1, 2], driving evolutionary innovation and important ecosystem functions [3–6]. The transient nature of establishment makes study of symbiotic origins difficult, but experimental comparison of independent origins could reveal the degree of convergence in the underpinning mechanisms [7, 8]. We compared the metabolic mechanisms of two independent origins of Paramecium bursaria-Chlorella photosymbiosis [9–11] using a reciprocal metabolomic pulse-chase method. This showed convergent patterns of nutrient exchange and utilization for host-derived nitrogen in the Chlorella genotypes [12, 13] and symbiont-derived carbon in the P. bursaria genotypes [14, 15]. Consistent with a convergent primary nutrient exchange, partner-switched host-symbiont pairings were functional. Direct competition of hosts containing native or recombined symbionts against isogenic symbiont-free hosts showed that the fitness benefits of symbiosis for hosts increased with irradiance but varied by genotype. Global metabolism varied more between the Chlorella than the P. bursaria genotypes and suggested divergent mechanisms of light management. Specifically, the algal symbiont genotypes either produced photo-protective carotenoid pigments at high irradiance or more chlorophyll, resulting in corresponding differences in photosynthetic efficiency and non-photochemical quenching among host-symbiont pairings. These data suggest that the multiple origins of P. bursaria-Chlorella symbiosis use a convergent nutrient exchange, whereas other photosynthetic traits linked to functioning of photosymbiosis have diverged. Although convergence enables partner switching among diverse strains, phenotypic mismatches resulting from divergence of secondary symbiotic traits could mediate host-symbiont specificity in nature. Sørensen et al. compare multiple independent evolutionary origins of Paramecium-Chlorella symbiosis to reveal the underpinning metabolic mechanisms. Although the independent origins use a convergent nutrient exchange, they have diverged in traits linked to photosynthesis, which could mediate host-symbiont specificity in nature.Natural Environment Research CouncilBiotechnology and Biological Sciences Research Counci