TLR1-induced chemokine production is critical for mucosal immunity against Yersinia enterocolitica.

Our gastrointestinal tract is a portal of entry for a number of bacteria and viruses. Thus, this tissue must develop ways to induce antigen-specific T cell and antibody responses quickly. Intestinal epithelial cells are a central player in barrier function and also in communicating signals from invading pathogens to the underlying immune tissue. Here we demonstrate that activation of Toll-like receptor 1 (TLR1) in the epithelium leads to the upregulation of the chemokine CCL20 during oral infection with Yersinia enterocolitica. Further, both neutralization of CCL20 using polyclonal antibody treatment and deletion of TLR1 resulted in a defect in CCR6+ dendritic cells (DCs), which produce innate cytokines that help to induce anti-Yersinia-specific T helper 17 (TH17) cells and IgA production. These data demonstrate a novel role for TLR1 signaling in the intestinal epithelium and demonstrate that together TLR1 and CCL20 are critical mediators of TH17 immunity through the activation and recruitment of DCs

Closed-Loop Optimization of Soft Sensor Morphology Using 3D Printing of Electrically Conductive Hydrogel

Soft sensing technologies provide a novel alternative for state estimation in wearables and robotic systems. They allow one to capture intrinsic state parameters in a highly conformable manner. However, due to the nonlinearities in the materials that make up a soft sensor, it is difficult to develop accurate models of these systems. Consequently, design of these soft sensors is largely user defined or based on trial and error. Since these sensors conform and take the shape of the sensing body, these issues are further exacerbated when they are installed. Herein, a framework for the automated design optimization of soft sensors using closed-loop 3D printing of a recyclable hydrogel-based sensing material is presented. The framework allows direct printing of the sensor on the sensing body using visual feedback, evaluates the sensor performance, and iteratively improves the sensor design. Following preliminary investigations into the material and morphology parameters, this is demonstrated through the optimization of a sensorized glove which can be matched to specific tasks and individual hand shapes. The glove's sensors are tuned to respond only to particular hand poses, including distinguishing between two similar tennis racket grip techniques

Metastability in Interacting Nonlinear Stochastic Differential Equations II: Large-N Behaviour

We consider the dynamics of a periodic chain of N coupled overdamped particles under the influence of noise, in the limit of large N. Each particle is subjected to a bistable local potential, to a linear coupling with its nearest neighbours, and to an independent source of white noise. For strong coupling (of the order N^2), the system synchronises, in the sense that all oscillators assume almost the same position in their respective local potential most of the time. In a previous paper, we showed that the transition from strong to weak coupling involves a sequence of symmetry-breaking bifurcations of the system's stationary configurations, and analysed in particular the behaviour for coupling intensities slightly below the synchronisation threshold, for arbitrary N. Here we describe the behaviour for any positive coupling intensity \gamma of order N^2, provided the particle number N is sufficiently large (as a function of \gamma/N^2). In particular, we determine the transition time between synchronised states, as well as the shape of the "critical droplet", to leading order in 1/N. Our techniques involve the control of the exact number of periodic orbits of a near-integrable twist map, allowing us to give a detailed description of the system's potential landscape, in which the metastable behaviour is encoded

Finite-temperature phase transitions in quasi-one-dimensional molecular conductors

Phase transitions in 1/4-filled quasi-one-dimensional molecular conductors are studied theoretically on the basis of extended Hubbard chains including electron-lattice interactions coupled by interchain Coulomb repulsion. We apply the numerical quantum transfer-matrix method to an effective one-dimensional model, treating the interchain term within mean-field approximation. Finite-temperature properties are investigated for the charge ordering, the "dimer Mott" transition (bond dimerization), and the spin-Peierls transition (bond tetramerization). A coexistent state of charge order and bond dimerization exhibiting dielectricity is predicted in a certain parameter range, even when intrinsic dimerization is absent.Comment: to be published in J. Phys. Soc. Jpn., Vol. 76 (2007) No. 1 (5 pages, 4 figures); typo correcte

WaterRenew : wastewater polishing using renewable energy crops

The research described in this thesis is part of a wider EU-LIFE project, the WaterRenew project. The WaterRenew concept can be described as the recovery of nutrients from wastewater which can lead to eutrophication of surface waters, by irrigation of short rotation coppice in order to fertilise them. Such systems have been proven to function properly as nutrient removal systems when studied for N removal and have already been successfully and commercially implemented in different countries. However, the factors potentially preventing them from operating sustainably have not been identified nor their upper limits quantified with confidence. A WaterRenew system can indeed be looked at as a unit composed with three main compartments; soil, soil water and plant. Therefore, the sustainability of such a system will be compromised if at least one of these compartments is changed irreversibly. The limits can be hydrological with constant runoff or drainage being induced. They can also be chemical with inadequate amounts of nutrients removed from the effluent applied or irreversible accumulation of nutrients in soil. Finally, these limits can be physiological with the trees’ health being irreversibly compromised. Moreover, the relevance and effectiveness of such a system under UK conditions has not been established yet. In this context, a field trial was set up at Cranfield University sewage treatment works where the secondary treated effluent was irrigated on to Salix viminalis, Populus trichocarpa and Eucalyptus gunnii trees planted at a density of 13,060 trees.ha-1, on a chalky clayey soil, in order to maintain soil water content at field capacity. To tackle more specifically P fate processes understanding, an independent P leaching soil column experiment was also set up. With the latter settings, it was possible to apply high volumes of effluent (3625 mm for willow, 2895 mm for poplar and 3345 mm for eucalyptus for the 2 years of irrigation) and high amounts of nutrients (1023 kg-N.ha-1 and 134 kg-P.ha-1 for willow, 834 kg- N.ha-1 and 108 kg-P.ha-1 for poplar and 946 kg-N.ha-1 and 127 kg-P.ha-1for eucalyptus for the 2 years of irrigation). It was found that irrigation with effluent increased significantly tree yields so that they were within the range reported in the literature for willow and eucalyptus but slightly lower for poplar. The trees uptook between 20 % and 50 % of the total amounts of N and P applied with eucalyptus uptaking more nutrients than willow, which in turn took up more than poplar. Then, it was found that irrigation did not have any significant effect on N and P in soil and the amounts applied remained very low compared to the existing nutrients soil pools. However, irrigation did have a significant effect on increasing K and Na in soil. Na increased enough to induce a significant increase in soil SAR but soil remained neither saline nor alkali. The trees had a smaller impact on soil chemistry. Finally, it was found also that irrigation did not have any significant effect on N and P in soil water with no P detectable in any of the soil water and groundwater samples during the whole experiment. Irrigation did, however, increase significantly K and Na concentrations in soil water and for K also in groundwater. From the point of view of nutrients removal, although a tree effect was measurable, it was not as important as the functions of the soil. Thus, when a WaterRenew system is maintained under a hydrological constraint, with the soil moisture kept at field capacity, it was still possible to apply high volumes of effluent, even on a clayey soil. In addition, the consequent high amounts of nutrients applied were efficiently retained between tree uptakes and mainly soil organic and inorganic nutrients’ pools. Indeed, the amounts of nutrients lost by drainage remained low (<10 % of the total amounts applied) for N and P and groundwater was efficiently protected from pollution on this site. On P dynamic processes understanding, it was found that P leaching patterns depend highly on soil moisture and to a lesser extent on the amount of P applied. When soil is saturated, P will start leaching even when applied at a very low concentration. A model, the WR_MODEL, was developed which integrates the observations, measurements and understanding of Cranfield University sewage treatment work field trial and soil column experiment into a model. The purpose of WR_model is to help the design and implementation of a WaterRenew system in any location as long as climatic and soil data are available. The model default values are for England and Wales climatic and soil data.EThOS - Electronic Theses Online ServiceGBUnited Kingdo