Measurement of Electron Clouds in Large Accelerators by Microwave Dispersion

Clouds of low energy electrons in the vacuum beam pipes of accelerators of positively charged particle beams present a serious limitation for operation at high currents. Furthermore, it is difficult to probe their density over substantial lengths of the beam pipe. We have developed a novel technique to directly measure the electron cloud density via the phase shift induced in a TE wave transmitted over a section of the accelerator and used it to measure the average electron cloud density over a 50 m section in the positron ring of the PEP-II collider at the Stanford Linear Accelerator Center

Pregabalin-induced trismus in a leukemia patient

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Intracellular innate resistance to bacterial pathogens

Mammalian innate immunity stimulates antigen-specific immune responses and acts to control infection prior to the onset of adaptive immunity. Some bacterial pathogens replicate within the host cell and are therefore sheltered from some protective aspects of innate immunity such as complement. Here we focus on mechanisms of innate intracellular resistance encountered by bacterial pathogens and how some bacteria can evade destruction by the innate immune system. Major strategies of intracellular antibacterial defence include pathogen compartmentalization and iron limitation. Compartmentalization of pathogens within the host endocytic pathway is critical for generating high local concentrations of antimicrobial molecules, such as reactive oxygen species, and regulating concentrations of divalent cations that are essential for microbial growth. Cytosolic sensing, autophagy, sequestration of essential nutrients and membrane attack by antimicrobial peptides are also discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71916/1/j.1462-5822.2006.00795.x.pd

Local analysis of the feasible primal-dual interior-point method

Abstract In this paper we analyze the rate of local convergence of the Newton primal-dual interior-point method when the iterates are kept strictly feasible with respect to the inequality constraints. It is shown under the classical conditions that the rate is q-quadratic when the functions associated to the binding inequality constraints are concave. In general, the q-quadratic rate is achieved provided the step in the primal variables does not become asymptotically orthogonal to any of the gradients of the binding inequality constraints. Some preliminary numerical experience showed that the feasible method can be implemented in a relatively efficient way, requiring a reduced number of function and derivative evaluations. Moreover, the feasible method is competitive with the classical infeasible primal-dual interior-point method in terms of number of iterations and robustness

Surface reconstruction of rotating objects from monocular video

The ability to model 3D objects from monocular video allows for a number of very useful applications, for instance: 3D face recognition, fast prototyping and entertainment. At present there are a number of methods available for 3D modelling from this and similar data. However many of them are either not robust when presented with real world data, or tend to bias their results to a prior model. Here we use energy minimisation of a restricted circular motion model to recover the 3D shape of an object from video of it rotating. The robustness of the algorithm to noise in the data and deviations from the assumed motion is tested and a 3D model of a real polystyrene head is created