Publications

To assess whether the persistence of Escherichia coli O157:H7 in soil amended with cattle slurry and ovine stomach content waste is affected by the presence of a maize rhizosphere.Cattle slurry and ovine stomach content waste were inoculated with E. coli O157:H7. Wastes were then applied to soil cores with and without established maize plants. The pathogen survived in soil for over 5 weeks, although at significantly greater numbers in soil receiving stomach content waste in comparison to cattle slurry. Persistence of the pathogen in soil was unaffected by the presence of a rhizosphere.Other factors may be more influential in regulating E. coli O157:H7 persistence in waste-amended soil than the presence or absence of a rhizosphere; however, waste type did have significant affect on the survival of E. coli O157:H7 in such soil.Escherichia coli O157:H7 can be present within animal-derived organic wastes that are routinely spread on land. Introduced measures with regards to such waste disposal may decrease exposure to the organism; however, the persistence of E. coli O157:H7 for considerable periods in waste-amended soil may still pose some risk for both human and animal infection. This study has shown that whilst survival of E. coli O157:H7 in waste-amended soil is not significantly affected by the presence or absence of a maize rhizosphere; it may vary significantly with waste type. This may have implications for land and waste management.

Urban wastewater contains a diverse array of human pathogenic viruses, often in high concentrations, presenting a significant challenge for water quality management. Sewage spills into natural water systems therefore pose a significant public health risk due to the potential to cause viral infections, yet the behaviour of viruses under dynamic environmental conditions remains poorly understood. This study investigates the decay of sewage-associated viruses (Adenovirus, Enterovirus, Hepatitis A Virus, Influenza A Virus, Norovirus GII, and Respiratory Syncytial Virus) in river, estuary, and marine water, with and without simulated sunlight. Using both qPCR and capsid integrity qPCR (CI-qPCR) methods, we found that in the absence of sunlight, time was the most significant factor influencing viral decay across all water types. The time required for a 90 % reduction in viral gene copies (T90) was observed within 0.3–24.3 days. Simulated sunlight accelerated viral decay, with significant reductions in gene copies l −1 observed within 1–3 days for all viruses studied, and T90 values ranging from 7 to 62.8 h. The effect of salinity on viral decay varied among viruses and water types. These results highlight the complex interplay between environmental water properties and viral persistence, emphasizing the critical role of solar radiation in viral inactivation. The study also demonstrates the value of using both qPCR and CI-qPCR methods to assess total and potentially infectious viral loads, respectively. These results have important implications for water quality management and public health risk assessment in diverse aquatic environments, particularly in the context of the increased frequency of sewage spills occurring in response to climate change and increasing urbanization. The data will support improvements in water quality modelling and associated risk management, contributing to more effective measures for protecting public health in coastal and inland water systems.

We construct a Bayesian estimator for the dilution of a wastewater sample, and use it to estimate the prevalence of SARS-CoV-2 in Wales using data from the Wales Environmental Wastewater Analysis and Surveillance for Health project (WEWASH). In Wales wastewater is diluted by rainwater so an estimate of the level of dilution is required if we are to normalise sample measurements of disease markers such as SARS-CoV-2 RNA. We consider the situation where flow measurements are available, but will regularly be unreliable because of the action of combined sewer outflows, which divert wastewater away from treatment plants when the flow is excessive. However we also have proxies for the flow from various chemical markers, whose level per unit of population is fixed. The new estimator has multiple advantages compared to existing procedures: credible intervals for the estimates; optimal weighting of the chemical markers; systematic handling of missing and censored values; and model based smoothing without lags.

No abstract is provided for this article.

Drainage and cultivation have turned peatlands from carbon (C) sinks into hotspots for greenhouse gas (GHG) emissions. Raising the water table and planting of winter cover crops are potential strategies to help reduce peat oxidation and re-initiate net C accumulation during the non-cropping period. However, the effects of these practices as well as their interactions on GHG emissions remain unclear. Here, we carried out an outdoor mesocosm experiment to elucidate the effect of water table levels (−30 cm and −50 cm) and winter cover crop cultivation (vetch, rye, no plant) on carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) fluxes during the winter period (November-April). Soil-atmosphere GHG exchange, GHG concentrations within the peat profile and soil water solute concentrations were monitored. Our results showed that high water table significantly reduced ecosystem respiration, while it had no net effect on N2O and CH4 fluxes. Uptake of available N by the cover crop significantly reduced nitrate in soil solution, thereby lowering the potential for leaching and both direct and indirect N2O emissions. No interactive effects between water table levels and cover crops were detected for any of the measured GHG fluxes. Seasonal variations of GHG fluxes were positively correlated with soil air concentrations at −15 cm and −40 cm depths, which were further regulated by dissolved organic C, nitrate concentration, and anaerobic conditions in the soil. This study suggests that there is great potential to raise water table levels and introduce green cover crops to reduce GHG emissions. Further studies are needed to achieve a complete evaluation of these strategies outside of the growing season, which may provide a significant mitigation benefit in C-rich cultivated peatlands.

There is ample experimental evidence for shifts in plant community composition under climate warming. To date, however, the underlying mechanisms driving t

Human enteric viruses are responsible for waterborne and shellfish-associated disease outbreaks worldwide. Quantitative reverse transcription PCR (qRT-PCR)

Summary Evidence suggests that frequent and direct exposure to domestic animals has made farmers less susceptible to symptomatic Escherichia coli O157 infection than other members of the community. We have quantified the seroprevalence of antibodies to E. coli O157 lipopolysaccharide (LPS) from a representative cohort of farm workers in three geographically distinct regions of the United Kingdom during two sampling rounds over a 2‐year period. All participants completed a questionnaire to determine the range and extent of recent animal contact alongside other potential occupational and environmental exposure routes. A total of 31/946 (3.3%) serum samples contained antibodies to E . coli O157 LPS (from both rounds combined). On the second sampling round, a significant difference in seropositivity was apparent between the three regions, with enhanced seroprevalence linked to recent contact with beef cattle, having a private water supply and contact with a child under 5 years old. Only five seropositive people reported symptoms of a gastrointestinal tract infection, although these symptoms were mild. These results further support the premise of acquired immunity to E . coli O157 associated with prolonged antigenic exposures within the farming environment.

Green manuring significantly increased rice yield and soil carbon (C) stocks, however, improper farming practices may result in elevated methane (CH4) emissions. This study investigated the effects of optimizing water management after green manure incorporation on soil quality index (SQI), rice productivity, C Footprint, net ecosystem economic budget (NEEB), and comprehensive evaluation index (CEI) over a 2-year period in a rice-green manure rotation system. A field experiment was conducted including five treatments: winter fallow-rice (WF) and green manure-single rice rotation combined with 0, 5, 10, and 15 days of delayed flooding after green manure incorporation (GM, GM-WM5, GM-WM10, GM-WM15). Compared with WF, green manuring treatments enhanced rice productivity and SQI. Delayed flooding following green manure incorporation achieved CH4 emission levels equal to or lower than those from WF, with emissions reduced by 37.7 %−76.1 % relative to GM. C Footprint and yield-scaled C Footprint lowered respectively from 43.9 t CO2-eq ha−1 and 2.7 kg CO2-eq kg−1 in GM to 9.8 −26.1 t CO2-eq ha−1 and 0.6 −1.6 kg CO2-eq kg−1 in delayed flooding managements, while NEEB increased by 1594 −2340 CNY ha−1 compared with GM. CEI showed the trend of WF < GM < GM-WM15 < GM-WM5 < GM-WM10. In conclusion, delayed flooding practice, especially delayed by 10 days after incorporating green manure, achieved a triple-win scenario for soil quality, rice productivity, and environmental benefits compared with traditional water management practices.

PKS 1934–638 is an archetypal GPS source, peaking at 1.4 GHz and exhibits almost no flux density variability. VLBI images at frequencies of .843, 2.3, 4.8, &amp; 8.4 were made with the southern hemisphere VLBI array and they reveal that the source is a 42 mas compact double. There is no detectable change in separation over the last 20 years, yielding an upper limit of ~ 0.03 c ± 0.2 c on any expansion velocity. The spectral shapes of the two components are remarkably similar, despite indications of finer structure on longer baselines. Magnetic field calculations indicate fields of a few mGauss and the results are consistent with equipartition.