The biological membrane is a highly organised structure. Many biologically active compounds interact with the biological membrane and modify its structure and organisation in a very selective manner. Phospholipids form the basic backbone structure of biological membranes. When phospholipid layers are adsorbed on a mercury drop electrode (HMDE) they form monolayers which have a very similar structure and properties to exactly half the phospholipid bilayer of a biological membrane. The reason for this is that the fluid phospholipid layer is directly compatible with the smooth liquid mercury surface. The great advantage of this system is that the structure of the adsorbed phospholipid layer can be very closely interrogated electrochemically since it is supported on a conducting surface. In this way interactions with biologically active compounds which modify the monolayer's structure can be sensed. The disadvantage is that Hg electrodes are fragile, toxic and have no applicability for field use in spite of the sensitivity of the system to biological membrane active species. Another disadvantage is that the Hg surface can only be imaged with extreme difficulty. This project takes the above proven sensing system and modifies it in the following way. A single and an array of platinum (Pt) microelectrode(s) are fabricated on a silicon wafer. On each microelectrode a minute amount of Hg is electrodeposited and on each Hg/Pt electrode a phospholipid monolayer is deposited. The stability of each phospholipid layer will be ensured through the edge effect of the electrode. We will use the silicon wafer array to carry out controlled phospholipid deposition experiments which are not possible on the HMDE. We shall also try out other methods of phospholipid deposition. The project will exploit the fact that the microelectrode array system with deposited phospholipid monolayers is accessible for imaging. AFM studies at Leeds have already been used to image temperature induced phase changes in mica supported phospholipid bilayers showing nucleation and growth processes. The AFM system is eminently suitable therefore to image the potential induced phase changes of the phospholipid monolayers on the individual chip based microelectrodes. It is important to do this because the occurrence of these phase transitions is very sensitive to the interaction of the phospholipid layer with biomembrane active species.In addition the mechanism of the phase changes which are fundamentally the same as those occurring in the electroporation of cells are of immense physical interest and a greater understanding of them can be gained through their imaging. We shall also attempt to image the interaction of the layer with membrane active peptides at different potential values. The AFM system will be developed to image the conformation and state of aggregation of adsorbed anti-microbial peptides on the monolayer in particular as a function of potential change. When biomembrane active compounds interact with phospholipid layers on Hg they alter the fluidity and organisation of the layers. This in turn affects the characteristics of the potential induced phase transitions. This can be very effectively monitored electrochemically by rapid cyclic voltammetry (RCV). Interferences to the analysis will be characterised. Pattern recognition techniques will be developed to characterise the electrochemical response to individual active compounds.The project will deliver a sensor on a silicon wafer which has the potential to detect low levels of biomembrane active organic compounds in natural waters and to assess the biomembrane activity of pharmaceutical compounds. The proven feasibility of cleaning the Hg/Pt electrode and renewing the sensing phospholipid layer will facilitate the incorporation of the device into a flow through system with a full automation and programmable operation.

AHRC : Jessica Robins : AH/R504671/1 "Breaking Eggs" is an exciting project sharing knowledge between the UK and Canada. The project invites residents of Guelph, Wellington to take part in a series of hands-on workshops responding to the beginning of Our Food Future project, a city wide, 5-year project that aims to use technological innovation to make the region a sustainable food hub for Canada. Our Food Future is a multi-million-dollar project that will use technology to radically change the way food is grown, distributed and consumed. The project will make Guelph the world's first circular food city, using technology to make sure everyone has enough to eat and waste is eliminated, while restoring natural systems. The workshops will use creative methods to help local community members explore the wider project and examine avenues for their engagement. It will look at what opportunities' residents could take advantage of, and what challenges communities could face during this transition. Breaking Eggs will take place in the first year of the Our Food Future project so will give residents of different local communities a chance to be involved in shaping the project. The workshops will invite people from all parts of Guelph and Wellington County to take part in sharing ideas and creating a new future for the region. The lessons learned through the project will be brought back to the UK and the knowledge gathered will be shared so that other communities can look at ways they can engage in more sustainable food systems for their region.

Iceland represents a natural laboratory for studying the colonization of freshwater habitats by fish since rivers and lakes all date from the end of the last Ice-Age less than 10,000 years ago. The North Atlantic provided a refuge for species such as arctic charr (Salvelinus alpinus) which invaded freshwater once the ice retreated. New habitats and the lack of competing species led to the appearance of different forms of Artic charr, called morphs. In particular, 27 discrete populations of dwarf charr have been identified with specialised feeding morphology that enables them to exploit the small larval fissures on the bottom of streams and lakes. Our Icelandic and Canadian partners have collected an enormous amount of data on each of the dwarf populations including, habitat characteristics (temperature and bottom type), diet, maximum body size, size and age at sexual maturity and cranial morphology. Other studies in progress on rapidly evolving DNA sequences we will enable us to determine the relationships between each population and estimate which ones arose independently allowing us to study the repeatability of evolution for populations living in similar habitats. Studies involving such diverse organisms as worms, flies and vertebrates suggest that poor nutrition alone is sufficient to produce dwarfism via effects on the signaling pathways controlled by the hormone Insulin-like growth factor-I (IGF-I): indicating a universal and conserved biological mechanism. Intriguingly, in the zebrafish, which is often used for studies of development, so-called 'knock-outs' of an IGF-binding-protein gene also caused alterations to the shape of the head which are reminiscent of those found in dwarf charr. We will therefore experimentally test the hypothesis that interactions between the environment and the IGF-hormone system during development can produce the specialised jaw and cranial morphology characteristic of the dwarf phenotype. Since early development in fish is entirely dependent on genetic messages passed through the egg yolk we will conduct experiments to determine whether it is the environment of the mother, the embryo or both that are important for producing fish with dwarf characteristics. Thingvallavatn, the largest and oldest lake in Iceland, contains four Arctic charr morphs, including a dwarf form, which are specialised to exploit different habitats. Laboratory breeding experiments have shown that the large differences in body size, morphology and life history such as the size at sexual maturity are heritable. This suggests that intense competition between morphs and reproductive isolation has resulted in natural selection and specialization for characters helping each morph to survive in their chosen environment. Previously we showed that dwarfism in the Thingvallavatn charr has resulted in a reduction in the number of muscle fibres in the trunk, which is thought to lower costs of maintenance relative to the ancestral charr. By studying a large number of Arctic charr populations (15 dwarfs and 5 generalists) we will test the generality of the hypothesis that the relative importance of developmental plasticity versus selection for setting muscle fibre number is related to the age and stability of the habitat and is different depending on whether there is competition with other morphs. The research is important because it addresses the fundamental question of how natural selection and plasticity operate to produce different forms of the same species at the level of physiological systems. The evolution of different morphs of the same species is relatively common and is found, for example, in sticklebacks and African cichclids. The practical application of this research is in understanding how the biodiversity of fish populations arises and how it may be conserved for future generations.

Through this project we are proposing two innovative technologies to be used to stop the spread of AMR pathogens in poultry chain viz. Hydroxyl radicals' technology from Canada, and a phage biosanitizer technology from the UK. Although aqueous-based hydroxyl radical systems are used frequently, the application in the gas phase is a relatively new development and hence more in-depth studies on the effectiveness of gas phase version on food commodities and their environments is needed. Poultry chain effectiveness will address AMR pathogens in the poultry chain. Late Prof William Waites of the University of Nottingham, UK was the first to see the potential of gas phase Advanced Oxidation Process (AOP) in food processing. The gas phase-hydroxyl radical process generates highly antimicrobial vapour through the ultraviolet light mediated degradation of hydrogen peroxide and ozone. The radicals inactivate microbes without leaving toxic residues. The technology is flexible and can be applied in the form of a tunnel, batch system or handheld device. In this project we will use Hydroxyl radicals to disinfect poultry environments, eggs, crates, poultry meat etc. The hydroxyl-radical treatment can effectively inactivate pathogens although there is no residual antimicrobial activity. Therefore, the application of bacteriophage post-hydroxyl radical treatment will act to prevent pathogens becoming re-established on the disinfected surface. Research by our Canadian partner has demonstrated effective AOP decontamination over a diverse range of fruit and vegetable types with an added benefit of extending shelf-life. Their current research has applied the same method for decontaminating shelled eggs, crates and poultry meat. Within the hatchery studies it has been demonstrated that the hydroxyl radical process can inactivate of Salmonella within 10s (5 log CFU reduction) without effecting the egg integrity or embryo development. Bacteriophages (phages in short) are naturally occurring bacterial viruses which specifically infect and kill bacteria leaving good microbes alone. This ability of the phages is being harnessed in controlling bacteria in various settings. The major concern for environmental application is method of application and viability of phages especially of the tailed phages. This project will explore the sustainable method of phage application through dry phage powder which could be dissolved into water during field application and also check the viability of tailed phages compared to non-tailed phages. Moreover, the strains of Salmonella and Campylobacter that will be targeted are the most prevalent in the UK and Canada which will be beneficial to the poultry chains in both the countries. The novelty of our dry phage powder approach lies in the development of cutting-edge prototype stable phage products that can be easily and cheaply incorporated into water for environmental spraying, or applied directly to animal carcasses to remove Salmonella and Campylobacter spp. This is important because traditionally phage products are unstable, and difficult to deliver to animals or applied to meat products, and thus potential benefits of using phages have been overshadowed by these hurdles needed to translate the science into a viable commercial product. The reason for using spray dried phages is that the technique is a highly scalable, widely used, efficient and inexpensive method. A stable phage product negates the need for complicated storage and it removes barriers for delivery. The feasibility of this method to produce powdered phages has already been proven in studies assessing the potential of processing into powders. We will integrate these two technologies wherein Hydroxyl radical technology (vapour based which is able to provide whole volume including air disinfection) and phage biosanitizers to control recontamination from re-introduction of day-of-hatch chicks into the environment would be possible.

Soils provide many functions for humans, including the storage of carbon and nutrient cycling, which are crucial for the production of food and mitigation of climate change. However, there is much concern that soils, and the functions that they provide, are being threatened by a range of pressures, including intensive farming methods and increased frequency of extreme climatic events, such as drought. Not only do these disturbances pose an immediate threat to the functioning of soils, but they could also impair their ability to resist and recover from further stresses that come in the future. Our project will tackle this problem by addressing two general questions: first, what makes a soil able to withstand and recover from disturbance events, such as drought, and, second how can we use this knowledge to ensure soils can buffer disturbances in the future? These are questions that have puzzled soil scientists for many years, but so far, remain unresolved. An area that offers much promise, however, in tackling this issue is food web ecology. Food webs are the networks of interactions describing who eats whom amongst the myriad organisms within an ecosystem. And in soil, they are the engine that drives the very processes of nutrient cycling and energy flow on which the functioning of soil and the terrestrial ecosystems they support, depend. It has been proposed for many years, but so far not fully tested in soil, that simple food webs are less able to withstand and recover from disturbance events, such as drought than complex ones. We want to test this theory in soil, which harbours some of the most complex, but also sensitive, food webs on Earth. We test the idea, through experiments and models, that the ability of a soil to withstand, recover and adapt to disturbance events depends on the architecture and diversity of the soil food web, which governs the rate of transfer of nutrients and energy through the plant-soil system. We also propose that soil disturbances associated with intensive land use, such as trampling and fertiliser addition, erode the very food web structures that make the soil system stable, thereby reducing the ability of soil to resist and recover from future disturbances, such as extreme weather events. We will also resolve what makes a food web stable, and test the roles of different types of organisms in soil, such as mycorrhizal fungi, which we believe play a major role. And finally, we will develop new models to help us better predict how soils will respond to future threats and to guide management decisions on sustainable soil management in a rapidly changing world. These question are at the heart of the NERC Soil Security programme which seeks to resolve what controls the ability of soils and their functions to resist, recover and ultimately adapt, to perturbations, such as those caused by land use and extreme climatic events.