Development and testing of a risk indexing framework to determine field-scale critical source areas of faecal bacteria on grassland.

This paper draws on lessons from a UK case study in the management of diffuse microbial pollution from grassland farm systems in the Taw catchment, south west England. We report on the development and preliminary testing of a field-scale faecal indicator organism risk indexing tool (FIORIT). This tool aims to prioritise those fields most vulnerable in terms of their risk of contributing FIOs to water. FIORIT risk indices were related to recorded microbial water quality parameters (faecal coliforms [FC] and intestinal enterococci [IE]) to provide a concurrent on-farm evaluation of the tool. There was a significant upward trend in Log[FC] and Log[IE] values with FIORIT risk score classification (r2 =0.87 and 0.70, respectively and P<0.01 for both FIOs). The FIORIT was then applied to 162 representative grassland fields through different seasons for ten farms in the case study catchment to determine the distribution of on-farm spatial and temporal risk. The high risk fields made up only a small proportion (1%, 2%, 2% and 3% for winter, spring, summer and autumn, respectively) of the total number of fields assessed (and less than 10% of the total area), but the likelihood of the hydrological connection of high FIO source areas to receiving watercourses makes them a priority for mitigation efforts. The FIORIT provides a preliminary and evolving mechanism through which we can combine risk assessment with risk communication to end-users and provides a framework for prioritising future empirical research. Continued testing of FIORIT across different geographical areas under both low and high flow conditions is now needed to initiate its long term development into a robust indexing tool

Selenium Enrichment of Laboratory Scale Silos Using Lactic Acid Bacteria Inoculum

Selenium (Se) is a trace element essential for normal cellular function, which has been linked with reduced risk of cancer, cardiovascular disease, cognitive decline and thyroid disease in humans. Se deficiency in livestock is associated with white muscle disease, retained placenta, ill-thrift and mastitis. Where Se status or bioavailability from the soil for plants is poor, livestock rely on supplemental Se in their diets either as sodium selenite (inorganic form) or seleno-yeast (organic form). As lactic acid bacteria have been shown to incorporate Se as either organic or elemental (Nano-Se) (Eszenyi et al., 2011) there may be potential to use silage inoculant bacteria to improve the Se status of feed to provide Se requirements to livestock. In a previous study (Fleming et al., 2015) LAB isolates were screened for their ability to convert inorganic sodium selenite into Nano-Se and organic-Se (predominately Selenocysteine). Based on this ability and reduced retardation on growth properties when the Se was added, three LAB were selected for the current study to determine their potential as silage inoculants to increase bioavailable forms of Se (Nano and organic) in silage

Graft copolymers of hydroxyethyl cellulose by a ‘grafting to’ method: 15N labelling as a powerful characterisation tool in ‘click’ polymer chemistry

We demonstrate how 15N labelling can be used to probe the success of ‘grafting to’ processes, through the preparation of well-defined graft copolymers of hydroxyethyl cellulose by combining RAFT polymerisation and copper-catalysed azide-alkyne cycloaddition (CuAAC). Using synthesised alkyne-functionalised chain transfer agents, short-chain (DP=10) poly(N-vinylpyrrolidone) (PVP) and poly(N-isopropyl acrylamide) (PNIPAAM) were prepared in high conversion in a controlled manner (ƉM of ~1.4 and 1.2 respectively). Separately, partially 15N-labelled N3-HEC was synthesised and characterised using solid state 13C, 15N CP-MAS NMR and FTIR spectroscopies. Alkyne-terminated PVP and PNIPAAM were grafted at different graft densities onto partially 15N-labelled N3-HEC using the click reaction. The hybrid HEC-g-polymer materials were fully characterised using solid state 13C and 15N CP-MAS NMR and FTIR spectroscopies. While 13C and FTIR spectroscopies gave indirect or weak evidence of CuAAC coupling, the cycloaddition of the alkyne-terminated polymers with N3-HEC was proven unambiguously by 15N solid state NMR spectroscopy. This indicates the utility of 15N labelling for probing the coupling efficiency of CuAAC reactions when employed in ‘grafting to’ processes with cellulosic substrates

High speed CO2 laser surface modification of iron/cobalt co-doped boroaluminosilicate glass

This document is the Accepted Manuscript version of a published work that appeared in final form in Laser Physics Letters. To access the final edited and published work see http://dx.doi.org/10.1088/1612-2011/13/7/076102A preliminary study into the impact of high speed laser processing on the surface of iron and cobalt co-doped glass substrates using a 60 W continuous wave (cw) CO2 laser. Two types of processing, termed fill-processing and line-processing, were trialled. In fill-processed samples the surface roughness of the glass was found to increase linearly with laser power from an Sa value of 20.8 nm–2.1 μm at a processing power of 54 W. With line processing, a more exponential-like increase was observed with a roughness of 4 μm at 54 W. The change in surface properties of the glass, such as gloss and wettability, have also been measured. The contact angle of water was found to increase after laser processing by up to 64°. The surface gloss was varied between 45 and 100 gloss units (GUs)

Enrichment of Lactic Acid Silage Bacteria with Selenium by Growing Cultures in Modified MRS Broth Supplemented with Sodium Selenite

Selenium (Se) is a trace element essential for normal cellular function, which has been linked with reduced risk of cancer, cardiovascular disease, cognitive decline and thyroid disease in humans. Se deficiency in livestock is associated with white muscle disease, retained placenta, ill-thrift and mastitis. Where Se status or bioavailability from the soil for plants is poor, livestock rely on supplemental Se in their diets either as sodium selenite (inorganic form) or seleno-yeast (organic form). As lactic acid bacteria have been shown to incorporate Se as either organic or elemental (Nano-Se), (Eszenyi et al., 2011) there may be potential to use silage inoculant bacteria to improve the Se status of feed to provide Se requirements to livestock. The aim of this experiment was to examine the growth, uptake of selenium as organic (selenocysteine and selenomethionine), inorganic (selenite and selenate) and Nano-Se by lactic acid bacterial isolates (LAB), which could then be used in future ensiling studies (Lee et al., 2015) to produce high Se silage

Does White Clover (Trifolium repens) Abundance in Temperate Pastures Determine Sitona obsoletus (Coleoptera: Curculionidae) Larval Populations?

To determine if host plant abundance determined the size of clover root weevil (CRW) Sitona obsoletus larval populations, a study was conducted over four years in plots sown in ryegrass (Lolium perenne) (cv. Nui) sown at either 6 or 30 kg/ha and white clover (Trifolium repens) sown at a uniform rate of 8 kg/ha. This provided a range of % white clover content to investigate CRW population establishment and impacts on white clover survival. Larval sampling was carried out in spring (October) when larval densities are near their spring peak at Lincoln (Canterbury, New Zealand) with % clover measured in autumn (April) and spring (September) of each year. Overall, mean larval densities measured in spring 2012, 2013, 2014 and 2015 were 310, 38, 59 and 31 larvae m-2, respectively. There was a significant decline in larval populations between 2012 and 2013, but spring populations were relatively uniform thereafter. The mean % white clover measured in autumns of 2012 to 2015 was 17, 10, 3 and 11%, respectively. In comparison, mean spring % white clover from 2012 to 2015, averaged c. 5% each year. Analysis relating spring (October) larval populations to % white clover measured in each plot in autumn (April) found the 2012 larval population to be statistically significantly larger in the ryegrass 6 kg/ha plots than 30 kg/ha plots. Thereafter, sowing rate had no significant effect on larval populations. From 2013 to 2015, spring larval populations had a negative relationship with the previous autumn % white clover with the relationship highly significant for the 2014 data. When CRW larval populations in spring 2013 to 2015 were predicted from the 2013 to 2015 autumn % white clover, respectively, based on their positive relationship in 2012, the predicted densities were substantially larger than those observed. Conversely, when 2015 spring larval data and % clover was regressed against 2012-2014 larval populations, observed densities tended to be higher than predicted, but the numbers came closer to predicted for the 2013 and 2014 populations. These differences are attributed to a CRW population decline that was not accounted by % white clover changes, the CR

Synthesis of 2,2-difluoro-1,3-diketone and 2,2-difluoro-1,3-ketoester derivatives using fluorine gas

Solutions of 1,3-diketones and 1,3-ketoester derivatives react with fluorine to give the corresponding 2,2-difluoro-1,3-dicarbonyl derivatives in the presence of quinuclidine. Quinuclidine reacts with fluorine in situ to generate a fluoride ion that facilitates limiting enolization processes, and an electrophilic N-F fluorinating agent that is reactive towards neutral enol species

Seasonal persistence of faecal indicator organisms in soil following dairy slurry application to land by surface broadcasting and shallow injection

Dairy farming generates large volumes of liquid manure (slurry), which is ultimately recycled to agricultural land as a valuable source of plant nutrients. Different methods of slurry application to land exist; some spread the slurry to the sward surface whereas others deliver the slurry under the sward and into the soil, thus helping to reduce greenhouse gas (GHG) emissions from agriculture. The aim of this study was to investigate the impact of two slurry application methods (surface broadcast versus shallow injection) on the survival of faecal indicator organisms (FIOs) delivered via dairy slurry to replicated grassland plots across contrasting seasons. A significant increase in FIO persistence (measured by the half-life ofE.coliand intestinal enterococci) was observed when slurry was applied to grassland via shallow injection, and FIO decay rates were significantly higher for FIOs applied to grassland in spring relative to summer and autumn. Significant differences in the behaviour ofE.coliand intestinal enterococci over time were also observed, withE.colihalf-lives influenced more strongly by season of application relative to the intestinal enterococci population. While shallow injection of slurry can reduce agricultural GHG emissions to air it can also prolong the persistence of FIOs in soil, potentially increasing the risk of their subsequent transfer to water. Awareness of (and evidence for) the potential for &lsquo;pollution-swapping&rsquo; is critical in order to guard against unintended environmental impacts of agricultural management decisions

Respiratory syncytial virus seasonality and prevention strategy planning for passive immunisation of infants in low-income and middle-income countries:a modelling study

BACKGROUND: Respiratory syncytial virus (RSV) represents a substantial burden of disease in young infants in low-income and middle-income countries (LMICs). Because RSV passive immunisations, including maternal vaccination and monoclonal antibodies, can only grant a temporary period of protection, their effectiveness and efficiency will be determined by the timing of the immunisation relative to the underlying RSV seasonality. We aimed to assess the potential effect of different approaches for passive RSV immunisation of infants in LMICs. METHODS: We included 52 LMICs in this study on the basis of the availability of RSV seasonality data and developed a mathematical model to compare the effect of different RSV passive immunisation approaches (seasonal approaches vs a year-round approach). For each candidate approach, we calculated the expected annual proportion of RSV incidence among infants younger than 6 months averted (effectiveness) and the ratio of per-dose cases averted between that approach and the year-round approach (relative efficiency). FINDINGS: 39 (75%) of 52 LMICs included in the study had clear RSV seasonality, defined as having more than 75% of annual RSV cases occurring in 5 or fewer months. In these countries with clear RSV seasonality, the seasonal approach in which monoclonal antibody administration began 3 months before RSV season onset was only a median of 16% (IQR 13-18) less effective in averting RSV-associated acute lower respiratory infection (ALRI) hospital admissions than a year-round approach, but was a median of 70% (50-97) more efficient in reducing RSV-associated hospital admissions per dose. The seasonal approach that delivered maternal vaccination 1 month before the season onset was a median of 27% (25-33) less effective in averting hospital admissions associated with RSV-ALRI than a year-round approach, but was a median of 126% (87-177) more efficient at averting these hospital admissions per dose. INTERPRETATION: In LMICs with clear RSV seasonality, seasonal approaches to monoclonal antibody and maternal vaccine administration might optimise disease prevention by dose given compared with year-round administration. More data are needed to clarify if seasonal administration of RSV monoclonal antibodies or maternal immunisation is programmatically suitable and cost effective in LMICs. FUNDING: The Bill & Melinda Gates Foundation, World Health Organization

Surface treatments to modulate bioadhesion: A critical review

On account of the recent increase in importance of biological and microbiological adhesion in industries such as healthcare and food manufacturing many researchers are now turning to the study of materials, wettability and adhesion to develop the technology within these industries further. This is highly significant as the stem cell industry alone, for example, is currently worth £3.5 million in the United Kingdom (UK) alone. This paper reviews the current state-of-the-art techniques used for surface treatment with regards to modulating biological adhesion including laser surface treatment, plasma treatment, micro/nano printing and lithography, specifically highlighting areas of interest for further consideration by the scientific community. What is more, this review discusses the advantages and disadvantages of the current techniques enabling the assessment of the most attractive means for modulating biological adhesion, taking in to account cost effectiveness, complexity of equipment and capabilities for processing and analysis