The design and synthesis of Novel AOX and cytochrome bc1 complex inhibitors which act as phytopathogenic fungicides

The metabolic pathway for oxidative phosphorylation has remained a reliable target for the development of novel fungicides. The reliance on single target site fungicides within this pathway has increased the selection pressure for point mutations within a number of key complexes, including the cytochrome bc1 complex. The alternative oxidase (AOX) provides an alternative route for respiration, introducing a mechanism by which selection pressure and pathogenicity can be increased. In particular, the fungal pathogen Septoria tritici has developed a highly fungicide resistant strain. The design and synthesis of inhibitors targeting the fungal AOX, or the AOX and the cytochrome bc1 complex, represents a new class of fungicides improving crop yield outcomes. Investigation into the AOX found in S. tritici (StAOX), led to new techniques to fully characterise and overexpress the protein in a haem deficient Escherichia coli strain, which has then been compared to that of the well-studied protozoan AOX, Trypanosoma brucei brucei (TAO). The enzymatic activity of StAOX was found to be significantly lower in comparison to AOXs from other species, but responded dramatically to the nucleotide regulators, GMP and IMP. The purified protein has also been shown to be sensitive to its lipid environment with full enzymatic recovery following re-introduction into a lipid membrane. The natural quinol analogue, ascofuranone, displays selectivity towards the AOX and was selected for further design and lead modification. Several ascofuranone derivatives were synthesised according to a new synthetic route. A variety of new methods were utilised to analyse the inhibitors providing IC50, KD, thermodynamic and cytotoxicity data. Two of the newly synthesised compounds provided selectivity for TAO over the cytochrome bc1 complex, but failed to show selectivity to the StAOX. In vitro data suggests a single phenylalanine residue restricts inhibitor’s tail length to within an 8-carbon chain length, supported by an in-silico docking screen

AMMONIA EMISSIONS FROM SLURRY APPLICATIONS TO LAND

Over the last 10-15 years there has been increasing concern within Europe as to the effects of ammonia emission and subsequent deposition to sensitive ecosystems, causing eutrophication and soil acidification. Transboundary transport of emissions has led to legislation at EC level with member states being given emission ceiling targets. Research has therefore aimed at quantifying national emissions, modelling emission processes and developing mitigation strategies. Agriculture accounts for >80% of total UK ammonia emission, therefore an accurate and robust model is required to estimate emissions from this sector. National inventory methodology has improved as the database of emission measurements and survey data has grown and as models have evolved from discrete empirical calculations for individual sources to linked nitrogen flow models incorporating more process-based algorithms. Ammonia emissions from agriculture derive mainly from livestock manures (primarily from the urea content of urine) and land application of manures represents a major emission source. Research in this area has therefore aimed to improve our ability to predict losses, taking into account the major influencing factors, in order to improve inventory estimates, improve manure management decision support models for farmers and advisers and to highlight potential mitigation strategies. This requires the ability to make precise, accurate measurements and measurement technology has been developed for a range of scales. A key factor influencing ammonia emissions following applications of livestock slurries to soil is the rate and extent to which slurry infiltrates into the soil, where it will be largely protected from volatilisation. This has not previously been fully incorporated into process-based models and research presented here has provided a mechanism describing the infitration process in which the slurry dry matter concentration and the nature of that dry matter are among the important influencing factors. Measures aimed at reducing emissions from land spreading are generally regarded as the most cost-effective means of reducing emissions from agriculture. A number of slurry application techniques aimed at reducing emissions have been developed and assessed against the conventional method of surface broadcasting. These new techniques rely on either reducing the exposed slurry surface area from which emission occurs, reducing the air flow and temperature at the emitting surface (thereby increasing the resistance to ammonia transport from the emitting surface to the free atmosphere) or increasing the contact between slurry and soil. A more holistic approach to reducing emissions is via dietary manipulation, with the aim of reducing both the amount and form of nitrogen excreted by livestock. This can result in lower ammonia emissions at all stages of manure management i.e. livestock housing, manure storage and application to land.BBSRC Institute of Grassland and Environmental Researc

Inventory of ammonia emissions from UK agriculture 2009

The National Ammonia Reduction Strategy Evaluation System (NARSES) model (spreadsheet version) was used to estimate ammonia (NH3) emissions from UK agriculture for the year 2009. Year-specific livestock numbers and fertiliser N use were added for 2009 and revised for previous years. The estimate for 2009 was 231.8 kt NH3, representing a 2.3 kt increase from the previously submitted estimate for 2008. Backward and forward projections using the 2009 model structure gave estimates of 317, 245 and 244 kt NH3 for the years 1990, 2010 and 2020, respectively. This inventory reports emission from livestock agriculture and from nitrogen fertilisers applied to agricultural land. There are a number of other minor sources reported as ‘agriculture’ in the total UK emission inventory, including horses not kept on agricultural holdings, emissions from composting and domestic fertiliser use

Diet Effects on Dairy Manure Nitrogen Excretion and Cycling

The amount and forms of (nitrogen) N excreted by ruminant livestock and post excretion manure N cycling are highly influenced by what is fed. For example, the relative amount of urinary N, faecal endogenous N of microbial and gut origin, and faecal undigested feed N is affected by how much dietary fibre and secondary compounds (e.g., tannins, polyphneolics) are consumed. Each manure N component has a different propensity for loss; for example via ammonia (NH3) volatilisation (Misselbrook et al., 2004), leaching, and cycles differently in the soil-plant continuum (Powell, 2003). We evaluated dairy diet effects on amount and forms of manure N excreted and post excretion cycling of manure N from different diets after application to soil

Site categorisation for nitrogen measures

Final report to Natural England on project IPENS-049

Strategies to reduce nutrient pollution from manure management in China

As the demand for livestock products continues to increase in China, so too does the challenge of managing increasing quantities of manure. Urgent action is needed to control point source (housing, storage and processing) and diffuse (field application) pollution and improve the utilization of manure nutrients and organic matter. Here, we review strategies to improve management at each stage of the manure management chain and at different scales. Many strategies require infrastructure investment, e.g., for containment of all manure fractions. Engineering solutions are needed to develop advanced composting systems with lower environmental footprints and design more efficient nutrient stripping technologies. At the field-scale, there is an urgent need to develop a manure nutrient recommendation system that accounts for the range of manure types, cropping systems, soils and climates throughout China. At the regional scale, coordinated planning is necessary to promote recoupling of livestock and cropping systems, and reduce nutrient accumulation in regions with little available landbank, while minimizing the risk of pollution swapping from one region to another. A range of stakeholders are needed to support the step change and innovation required to improve manure management, reduce reliance on inorganic fertilizers, and generate new business opportunities

Experience of Wellbeing and Spirituality in Ayahuasca Use

Background: Spirituality is an important area of investigation in relation to health, the study of which is being requested by clients accessing services as well as large healthcare organisational bodies such as the NHS and the Royal College of Psychiatrists (RCPsych). Its relationship to health and wellbeing is regularly reported as significant yet is poorly understood. Intersecting with this, is the recent re-emergence of psychedelic research as an area for therapeutic use, with recent research suggesting clinical outcomes may be associated with spiritual or ‘mystical-type’ experiences. Ayahuasca practice provides a clear research focal point to investigate reported spiritual phenomena and wellbeing and how these may intersect. Aims: The aim of this research was to explore people’s experience of wellbeing and spirituality in Ayahuasca use using Interpretive Phenomenological Analysis (IPA). Method: Semi-structured interviews of 7 UK-based individuals who have used Ayahuasca for both spiritual and wellbeing reasons, (self- reported), were conducted and transcripts analysed using Interpretive Phenomenology Analysis (IPA). Findings: Four main experiential themes were identified; 1) Connection, (direct, re-connection, and interconnection), 2) Wellbeing- functional applications 3) A relational Process, 4) ‘More than just Ayahuasca’ Implications: These finding contribute to the burgeoning field of psychedelic research and spiritual research as data suggests for some, psychedelic use is a spiritual phenomenon (not solely a pharmacological or psychological experience) and that aspects of self-reported spirituality have a significant role in individual wellbeing, lifestyle, and sense of meaning, which can be complicated to navigate, may change over time and may be associated with stigma. Key Search Terms: Spirituality, Ayahuasca, Psychedelics, Wellbein

Assessment of nitrogen uptake and biological nitrogen fixation responses of soybean to nitrogen fertiliser with SPACSYS

Chemical fertiliser nitrogen addition will inhibit biological nitrogen fixation (BNF) for soybean (Glycine max [L.] Merr) growth. The optimal balance of these two nitrogen input sources has been a key issue for sustainable development in Northeast China. We used the data collected from a four-year experiment with varied irrigation and fertiliser treatments from 2007 to 2010 to evaluate the SPACSYS model. The validated model was run to investigate the responses to different management practices in seed yield, BNF, nitrogen content in seed and soil nitrogen budgets. Scenario testing showed average yield increase of 2.4% - 5.2% with additional 50-100 kg N/ha application. Irrigation at the reproductive stage improved seed yield in drier years with an increase of 12-33% compared with the rain-fed treatment. BNF was suppressed by fertiliser nitrogen application and drought stress with a decrease of 6-33% and 8-34%, respectively. The average nitrogen budget without fertilization indicated a deficit of 39 kg N/ha. To attain higher seed yield, applying fertiliser at 25-30 and 15-20 kg N/ha before sowing is advised in drier and wetter years, respectively. To achieve a higher seed nitrogen content, an application rate of 55-60 and 45-50 kg N/ha is recommended for drier and wetter years, respectively