Publications

Although S deficiency has been reported in plants worldwide, the belowground biogeochemical cycling of S is not well known. The combined use of mineral fertiliser and manure is regarded as a suitable fertilisation strategy to maintain agricultural soil productivity. A long-term (1964–2018) field experiment was selected to determine how manure application affects soil gross S mineralisation and immobilisation, and plant-derived organic S, cysteine (Cys), and methionine (Met) biological decomposition by 35S, 14C, and 15N labelling. High organic manure application did not increase organic S content in the topsoil owing to the high mineralisation rate, but it increased the organic S content in subsoil where mineralisation rates were relatively lower. S immobilisation dominated gross S fluxes, and the highest SO4 2− immobilisation rates were recorded under medium manure application. Most plant-derived protein S was decomposed to SO4 2− after 15 min, and only approximately 30% was retained in the microbial biomass. Protein bioavailability may have a more dominant role in soil S mineralisation than soil S-containing amino acids, owing to its higher concentration. The immobilisation of SO4 2− was considerably slower than that of proteins and amino acids, which indicates that the microorganisms preferred organic S over inorganic S and that the use is driven by C demand rather than S demand. Moreover, the microbial community released SO4 2− and NH4 + after taking up Cys and Met, and the imbalance of elements between substrates and microbes played a dominant role in soil S cycling. This process was strongly regulated by the nature of the substrate; less SO4 2− was released from Met than from Cys. Among the three important processes for organic S decomposition—the uptake by microorganisms, SO4 2− release, and SO4 2− reuse—manure application had a greater effect on SO4 2− release during organic S decomposition. Overall, manure application increased S bioavailability owing to high S fluxes, and high- and low-molecular weight organic S could be rapidly decomposed to SO4 2−.

Polar ecosystems are currently experiencing some of the fastest rates of climate warming. An increase in soil temperature in High Arctic regions may stimulate soil permafrost melting and microbial activity, thereby accelerating losses of greenhouse gases. It is therefore important to understand the factors regulating the rates of C turnover in polar soils. Consequently, our aims were to: (1) assess the concentration of low molecular weight (MW) dissolved organic carbon (DOC) in soil, (2) to investigate the temperature-dependent turnover of specific low MW compounds, and (3) to analyse the influence of substrate concentration on C cycling. Microbial mineralisation of labile low MW DOC in two High Arctic tundra soils was investigated using soil solutions spiked with either 14C-labelled glucose or amino acids. Spiked solutions were added to the top- and sub-soil from two ecosystem types (lichen and Carex dominated tundra), maintained at three temperatures (4–20°C), and their microbial mineralisation kinetics monitored. 14CO2 evolution from the tundra soils in response to 14C-glucose and -amino acid addition could best be described by a double first order exponential kinetic equation with rate constants k 1 and k 2. Both forms of DOC had a short half-life (t 1/2) in the pool of microbial respiratory substrate (t 1/2 =1.07±0.10h for glucose and 1.63±0.14h for amino acids; exponential coefficient k 1 =0.93±0.07 and 0.64±0.06h−1 respectively) whilst the second phase of mineralisation, assumed to be C that had entered the microbial biomass, was much slower (average k 2 =1.30×10−3 ±0.49×10−4 h−1). Temperature had little effect on the rate of mineralisation of 14C used directly as respiratory substrate. In contrast, the turnover rate of the 14C immobilized in the microbial biomass prior to mineralisation was temperature sensitive (k 2 values of 0.99×10−3 h−1 and 1.66×10−3 h−1 at 4 and 20°C respectively). Concentration-dependent glucose and amino acid mineralisation kinetics of glucose and amino acids (0–10mM) were best described using Michaelis–Menten kinetics; there was a low affinity for both C substrates by the microbial community (K m =4.07±0.41mM, V max =0.027±0.005mmol kg−1 h−1). In conclusion, our results suggest that in these C limiting environments the flux of labile, low MW DOC through the soil solution is extremely rapid and relatively insensitive to temperature. In contrast, the turnover of C incorporated into higher molecular weight microbial C pools appears to show greater temperature sensitivity.

Prions represent the active agent in transmissible spongiform encephalopathy (TSE) diseases and can remain infective to mammals even after prolonged periods in soil. The influence of mesofauna on prion dispersal and degradation in soil, however, remains unknown. In this study the effect of earthworms on the retention/dissemination of TSEs in soil was evaluated using a model recombinant prion protein (recPrP) and aqueous extracts from soil and fresh casts of two earthworm species, Lumbricus terrestris and Aporrectodea caliginosa. Our results showed that earthworm gut-derived enzymes did not enhance the degradation of recPrP in comparison to soil, even though non-prion related proteolytic activity was higher in fresh worm excrements than in soil samples. Complete degradation of recPrP occurred in the aqueous extracts from all samples within up to 6 days at +15 °C. The proteolytic enzymes responsible for degrading recPrP were inhibited by aprotinin and leupeptin and studies in pure cultures suggested these were most probably of soil microbial origin.

Prescribed fire is used to reduce the rate of woody plant encroachment in grassland ecosystems. However, fire is challenging to apply in continuously grazed pastures because of the difficulty in accumulating sufficient herbaceous fine fuel for fire. We evaluated the potential of rotationally grazing cattle in fenced paddocks as a means to defer grazing in selected paddocks to provide fine fuel for burning. Canopy cover changes from 1995 to 2000 of the dominant woody plant, honey mesquite (Prosopis glandulosa Torr.), were compared in three landscape-scale grazing and mesquite treatment restoration strategies: 4-paddock, 1-herd with fire (4:1F), 8-paddock, 1-herd with fire (8:1F), and 4:1 with fire or aerial application of 0.28kg · ha−1 clopyralid + 0.28kg · ha−1 triclopyr herbicide (4:1F/H), and a continuously grazed control with mesquite untreated (CU). Prescribed burning took place in late winter (February–March). Droughts limited burning during the 5-yr period to half the paddocks in the 4:1F and 8:1F strategies, and one paddock in each 4:1F/H strategy. Mesquite cover was measured using digitized aerial images in 1995 (pretreatment) and 2000. Mesquite cover was reduced in all paddocks that received prescribed fire, independent of grazing strategy. Net change in mesquite cover in each strategy, scaled to account for soil types and paddock sizes, was +34%, +15%, +5%, and -41% in the CU, 4:1F, 8:1F, and 4:1F/H strategies, respectively. Thus, rotational grazing and fire strategies slowed the rate of mesquite cover increase but did not reduce it. Fire was more effective in the 8:1F than the 4:1F strategy during drought because a smaller portion of the total management area (12.5% vs. 25%) could be isolated to accumulate fine fuel for fire. Herbaceous fine fuel and relative humidity were the most important factors in determining mesquite top-kill by fire.

A ribbon fiber with an array of ten Yb-doped cores has been operated in a laser configuration pumped by a diode-stack at 940 nm. 100 W of output power for /spl sim/260 W of launched pump has been achieved.

Fatty acids represent major components of cell membranes, serve as energy sources, modulate gene transcription and cell signalling and act as cytokine precursors. It is increasingly apparent that dietary fatty acids influence these vital functions and affect human health. Consequently, analytical techniques are required to identify and quantify the suite of fatty acids present in food and human tissues. Advances in mass spectrometry (MS) offer new opportunities to profile and quantify fatty acids in biological samples. Our aim was to demonstrate the use of GC- atmospheric pressure chemical ionisation (APCI)-ion mobility spectrometry (IMS)-TOF-MS to provide highly specific and sensitive quantification of known fatty acids plus a comprehensive overview of all the eluted analytes. Ionisation was achieved using an APCI source. This new approach was demonstrated on a range of commercial edible oils. Compared to standard GC techniques using flame ionisation detection (FID) or a single quadrupole MS with electron ionisation, GC-APCI-IMS-TOF-MS greatly increased compound selectivity and specificity, leading to greatly enhanced confidence in fatty acid methyl esters (FAME) identification and quantification. Our approach also added the fingerprint of high-resolution accurate mass (HRAM) discovery data, with collision cross section (CCS) values, relating to many other analytes. This method can be readily applied to study food provenance, food fraud and to identify fatty acid related illnesses.

The impact of increasing amounts of labile C input on priming effects (PE) on soil organic matter (SOM) mineralization remains unclear, particularly under anoxic conditions and under high C input common in microbial hotspots. PE and their mechanisms were investigated by a 60-day incubation of three flooded paddy soils amended with13C-labeled glucose equivalent to 50–500% of microbial biomass C (MBC). PE (14–55% of unamended soil) peaked at moderate glucose addition rates (i.e., 50–300% of MBC). Glucose addition above 300% of MBC suppressed SOM mineralization but intensified microbial N acquisition, which contradicted the common PE mechanism of accelerating SOM decomposition for N-supply (frequently termed as “N mining”). Particularly at glucose input rate higher than 3 g kg−1 (i.e., 300–500% of MBC), mineral N content dropped on day 2 close to zero (1.1–2.5 mg N kg−1) because of microbial N immobilization. To cope with the N limitation, microorganisms greatly increased N-acetyl glucosaminidase and leucine aminopeptidase activities, while SOM decomposition decreased. Several discrete peaks of glucose-derived CO2 (contributing >80% to total CO2) were observed between days 13–30 under high glucose input (300–500% of MBC), concurrently with CH4 peaks. Such CO2 dynamics was distinct from the common exponential decay pattern, implicating the recycling and mineralization of 13C-enriched microbial necromass driven by glucose addition. Therefore, N recycling from necromass was hypothesized as a major mechanism to alleviate microbial N deficiency without SOM priming under excess labile C input. Compound-specific 13C-PLFA confirmed the redistribution of glucose-derived C among microbial groups, i.e., necromass recycling. Following glucose input, more than 4/5 of total 13C-PLFA was in the gram-negative and some non-specific bacteria, suggesting these microorganisms as r-strategists capable of rapidly utilizing the most labile C. However, their 13C-PLFA content decreased by 70% after 60 days, probably as a result of death of these r-strategists. On the contrary, the 13C-PLFA in gram-positive bacteria, actinomycetes and fungi (K-strategists) was initially minimal but increased by 0.5–5 folds between days 2 and 60. Consequently, the necromass of dead r-strategists provided a high-quality C–N source to the K-strategists. We conclude that under severe C excess, N recycling from necromass is a much more efficient microbial strategy to cover the acute N demand than N acquisition from the recalcitrant SOM.

The anaerobic digestion of food waste converts waste products into 'green' energy. Additionally, the secondary product from this process is a nutrient-rich digestate, which could provide a viable alternative to synthetically-produced fertilisers. However, like fertilisers, digestate applied to agricultural land can be susceptible to both ammonia (NH3) and nitrous oxide (N2O) losses, having negative environmental impacts, and reducing the amount of N available for crop uptake. Our main aim was to assess potential methods for mitigating N losses from digestate applied to a winter wheat crop and subsequent impact on yield. Plot trials experiments were conducted at two UK sites, England (North Wyke-NW) and Wales (Henfaes-HF), to assess NH3 and N2O losses, yield and N offtake following a single band-spread digestate application. Treatments examined were digestate (D), acidified-digestate (AD), digestate with the nitrification inhibitor DMPP (D+NI), AD with DMPP (AD+NI), and a zero-N control (C). Determination of N losses was conducted using wind tunnels for NH3, and static manual and automatic chambers for N2O. The N offtake in both grain and straw was also measured. Ammonium nitrate (NH4NO3) fertiliser N response plots (from 75 to 300 kg N ha−1) were included to compare yields with the organic N source. Across both sites, cCumulative NH3-N losses were 27.6 % from D and D+NI plots and 1.5 % for AD and AD+NI of the total N applied, a significant reduction of 95 % with acidification. Cumulative N2O losses, varied between 0.13 and 0.35 % of the total N applied and were reduced by 50 % with the use of DMPP although the differences were not significant. Grain yields for the digestate treatments were 7.52 – 9.21 and 7.23 – 9.23 t DM ha−1 at HF and NW, respectively. Yields were greater from the plots receiving acidified-digestate relative to the non-acidified treatments but the differences were not significant. The yields (as a function of the N applied with each treatment) obtained for the digestate treatments ranged between 84.2 % (D+NI) and 103.6 % (D) of the yields produced by the same N rate from an inorganic source at HF. Advanced processing of digestate

Wastewater-based epidemiology has become an important tool for the surveillance of SARS-CoV-2 outbreaks. However, the detection of viruses in sewage is challenging and to date there is no standard method available which has been validated for the sensitive detection of SARS-CoV-2. In this paper, we describe a simple concentration method based on polyethylene glycol (PEG) precipitation, followed by RNA extraction and a one-step quantitative reverse transcription PCR (qRT-PCR) for viral detection in wastewater. PEG-based concentration of viruses is a simple procedure which is not limited by the availability of expensive equipment and has reduced risk of disruption to consumable supply chains. The concentration and RNA extraction steps enable 900-1500× concentration of wastewater samples and sufficiently eliminates the majority of organic matter, which could inhibit the subsequent qRT-PCR assay. Due to the high variation in the physico-chemical properties of wastewater samples, we recommend the use of process control viruses to determine the efficiency of each step. This procedure enables the concentration and the extraction the DNA/RNA of different viruses and hence can be used for the surveillance of different viral targets for the comprehensive assessment of viral diseases in a community.

A sample of 38 southern peaked-spectrum radio sources from the Parkes Catalogue have been observed using single-baseline VLBI. Thirty three objects were successfully detected on baselines of > 30 Mλ at 2.3 GHz. For 21 of these sources, the flux density in the...

Biochar application is not only being widely promoted as an ideal strategy to mitigate global climate warming, but it also has the advantage of reducing heavy metal bioavailability and migration in the soil. However, studies on the effects of field aging on biochar to reduce heavy metals from the soil are still limited. The present study aimed to explore the effects and mechanisms of aged biochar added to the soil planted with pepper plants on cadmium (Cd) uptake. To achieve this, un-amended soil (control), soil amended with fresh biochar, and aged biochar (biochar recovered from a long-term field trial after 9 years) were used to investigate the effects of field aging on biochar adsorption efficiency. The results revealed that the amount of Cd in the plant planted in control soil, amended with fresh and aged biochar, accounted for 40 ± 6.10, 17.18 ± 1.19, and 18.68 ± 0.79, respectively. There was a significant difference (P < 0.05) in the amount of Cd that was uptaken by plants among all treatments. However, soil amended with fresh biochar significantly (P < 0.05) decreased the amount of Cd in plants compared with soil amended with aged biochar. This indicates that field aging declines the potential of biochar to lower heavy metal bioavailability and retention in the soil. This study demonstrates that long-term burial lessens the ability of biochar to interact with Cd and suggests that biochar amendment can lower Cd in the soil, depending on the freshness and aging of biochar.

The COVID-19 pandemic demonstrated the need for rapid molecular diagnostics. Vaccination programs can provide protection and facilitate the opening of society, but newly emergent and existing viral variants capable of evading the immune system endanger their efficacy. Effective surveillance for Variants of Concern (VOC) is therefore important. Rapid and specific molecular diagnostics can provide speed and coverage advantages compared to genomic sequencing alone, benefitting the public health response and facilitating VOC containment. Here we expand the recently developed SARS-CoV-2 CRISPR-Cas detection technology (SHERLOCK) to provide rapid and sensitive discrimination of SARS-CoV-2 VOCs that can be used at point of care, implemented in the pipelines of small or large testing facilities, and even determine the proportion of VOCs in pooled population-level wastewater samples. This technology complements sequencing efforts to allow facile and rapid identification of individuals infected with VOCs to help break infection chains. We show the optimisation of our VarLOCK assays (Variant-specific SHERLOCK) for multiple specific mutations in the S gene of SARS-CoV-2 and validation with samples from the Cardiff University Testing Service. We also show the applicability of VarLOCK to national wastewater surveillance of SARS-CoV-2 variants and the rapid adaptability of the technique for new and emerging VOCs.

738 Background: An understanding of the relationship between breast cancer (BC) recurrence and mortality in pts with early BC is important. The objective of this study, therefore, was to evaluate this relationship among a mid-western health system population. Methods: A retrospective cohort study of 1616 pts (mean age 60 yrs) with early BC (stage I and II) was conducted using data from a large integrated health care system. Information on demographics, disease characteristics/treatment, evidence/type of recurrence, and death was obtained. Kaplan-Meier estimates were used to compare overall and BC-related mortality between recurrence types, and also between each recurrence type and a control group without recurrence. For each comparison, hazard ratios (HR) were estimated after controlling for baseline covariates. Results: During a median follow-up of 44.5 (range 6.1–98.3) months, there were 192 (11.9%) recurrence events (26.1% loco-regional, 15.6% contralateral, 58.3% distant) and 188 (11.6%) deaths due to any cause, of which 85 (5.3% of study population) were BC-related. Compared with the non-recurrence group, the distant recurrence group showed the highest risk of death (HR=13.6, p<.001), followed by the loco-regional recurrence group (HR=4.5, p<.001), and the contralateral recurrence group (HR=3.0, p=.01). The 5-year overall survival probability for distant, loco-regional, contralateral recurrence, and pts without recurrence was 41.3%, 59.3%, 83.4%, and 91.7%, respectively. Median time to all-cause mortality for pts with distant, loco-regional, and contralateral recurrence was 41.2, 76.9, and 89.5 months, respectively. A similar trend was observed for BC-related mortality, with a significantly higher risk of BC-related death in the distant recurrence group vs women with loco-regional recurrence (HR=3.6, p<.001). Conclusion: The study shows that BC recurrence, irrespective of type of recurrence, is associated with increased mortality in pts with early BC. This effect on mortality is substantially more pronounced in pts with distant recurrence. Therapies shown to reduce the risk of BC recurrence are likely to have a significant beneficial effect on survival in pts with early BC. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration AstraZeneca AstraZeneca AstraZeneca AstraZeneca

Agricultural soil emissions are a balance between sinks and sources of greenhouse gases (GHGs). The fluxes of GHGs from soils are complex and spatially and temporally heterogenous. While the soil surface is the exchange site with the atmosphere and is commonly where GHG fluxes are measured, it is important to consider processes occurring throughout the soil profile. To reduce emissions and improve agricultural sustainability we need to better understand the drivers and dynamics (production, consumption, diffusion) of these gases within the soil profile. Due to the heterogeneous nature of GHG processes at small to large scales, it is important to test how these processes differ with depth in different systems. In this study, we measured in situ CO2, N2O and CH4 concentration gradients as a function of soil depth over subsequent maize and wheat growing seasons with active gas samplers inserted into an arable field at 10, 20, 30 and 50 cm depths. We found N2O and CH4 concentrations increased with depth, but only CO2 concentrations differed with depth between growing seasons due likely to differences in soil diffusivity driven by soil conditions. Using the concentration gradient method (GM), the CO2 fluxes at each depth and their contribution to the surface flux were calculated and validated against a chamber method (CM) measured surface flux. We found the GM estimated surface CO2 flux was only 6 % different in the wheat, but 28 % lower than the surface measured flux in the maize growing season, due to drought conditions reducing the accuracy of the GM. Finally, we measured fluxes of CO2, N2O and CH4 in ambient and highly concentrated headspaces in laboratory mesocosms over a 72 h incubation period. We provide evidence of depth dependent CH4 oxidation and N2O consumption and possibly CO2 fixation. In conclusion, our study provides valuable information on the applicability of the GM and further evidence of the GHG production, consumption and diffusion mechanisms that occur deeper in the soil in a temperate arable context.