The role of bacterial secretion systems in the virulence of Gram-negative airway pathogens associated with cystic fibrosis

Cystic fibrosis (CF) is the most common lethal inherited disorder in Caucasians. It is caused by mutation of the CF transmembrane conductance regulator (CFTR) gene. A defect in the CFTR ion channel causes a dramatic change in the composition of the airway surface fluid, leading to a highly viscous mucus layer. In healthy individuals, the majority of bacteria trapped in the mucus layer are removed and destroyed by mucociliary clearance. However, in the lungs of patients with CF, the mucociliary clearance is impaired due to dehydration of the airway surface fluid. As a consequence, patients with CF are highly susceptible to chronic or intermittent pulmonary infections, often causing extensive lung inflammation and damage, accompanied by a decreased life expectancy. This mini review will focus on the different secretion mechanisms used by the major bacterial CF pathogens to release virulence factors, their role in resistance and discusses the potential for therapeutically targeting secretion systems

Point triangulation through polyhedron collapse using the l∞ norm

Multi-camera triangulation of feature points based on a minimisation of the overall l(2) reprojection error can get stuck in suboptimal local minima or require slow global optimisation. For this reason, researchers have proposed optimising the l(infinity) norm of the l(2) single view reprojection errors, which avoids the problem of local minima entirely. In this paper we present a novel method for l(infinity) triangulation that minimizes the l(infinity) norm of the l(infinity) reprojection errors: this apparently small difference leads to a much faster but equally accurate solution which is related to the MLE under the assumption of uniform noise. The proposed method adopts a new optimisation strategy based on solving simple quadratic equations. This stands in contrast with the fastest existing methods, which solve a sequence of more complex auxiliary Linear Programming or Second Order Cone Problems. The proposed algorithm performs well: for triangulation, it achieves the same accuracy as existing techniques while executing faster and being straightforward to implement

Variational multi-image stereo matching

In two-view stereo matching, the disparity of occluded pixels cannot accurately be estimated directly: it needs to be inferred through, e.g., regularisation. When capturing scenes using a plenoptic camera or a camera dolly on a track, more than two input images are available, and - contrary to the two-view case -pixels in the central view will only very rarely be occluded in all of the other views. By explicitly handling occlusions, we can limit the depth estimation of pixel (P) over right arrow to only use those cameras that actually observe (p) over right arrow. We do this by extending variational stereo matching to multiple views, and by explicitly handling occlusion on a view-by-view basis. Resulting depth maps are illustrated to be sharper and less noisy than typical recent techniques working on light fields

Indie Eh? Some Kind of Game Studies.

This introduction to this special issue of Loading... considers the articles of the issue in the context of game studies’ growing interest in, and implication with, the cultures of independent game development and the ‘indie scene’ in general. ‘Indie’ is the question not the answer for the authors of this issue. Together the articles herald a long term collaborative program of research that implicates concerns with the discrete and varied cultural contexts of game production, a recognition of the nuances and diversity in the tastes and values of players, and the place of digital games and game discourses in shaping and reshaping the public sphere. After this issue, we may argue about whether game studies has finally found its object but we can all agree that our engagement with the question of ‘indie’ has intriguing implications for the future of our work as games researchers, designers and cultural political actors

Wii are out of Control: Bodies, Game Screens and the Production of Gestural Excess

This paper looks at the ways that the Nintendo Wii might shift the locus of game analysis away from the screen and more towards players’ corporeal relationship to the screen. The Wii hardware and software, the television screen, the physical space and players’ bodies constitute an intriguing form of kinaesthetic play that borrows from cultural fantasies about virtual reality. This play, while conditioned by the goal driven and control logics of gameplay nevertheless leads to a production of ‘gestural excess’ as bodies twist, contort and perform in ways that the game as such neither demands nor necessarily accommodates

Never Playing Alone: The Social Contextures of Digital Gaming

Digital game studies does not quite have the same legacy of metaphors as Internet studies does and to some extent we find ourselves borrowing the idea that there is the concrete material place of the user/player on the one hand and the more abstract representational space of the game on the other. If the game is online then that space (given its properties of shared visual verisimilitude, interactivity and immersion) seems in fact more cyber-spatial (in the terms described by Neal Stephenson or William Gibson) than most Internet researchers could ever imagine. It is in this sense, that massively multiplayer online games like Everquest, Star Wars Galaxies or even the Sims Online, more so than websites, MUDs or even spatially intensive games like Myst, are commonly described in terms similar to how one might describe travelling to another country. Indeed, it would seem that the more immersive the game the greater this sense of transportation becomes

The cost of a large-scale hollow fibre MBR

A cost sensitivity analysis was carried out for a full-scale hollow fibre membrane bioreactor to quantify the effect of design choices and operational parameters on cost. Different options were subjected to a long term dynamic influent profile and evaluated using ASM1 for effluent quality, aeration requirements and sludge production. The results were used to calculate a net present value (NPV), incorporating both capital expenditure (capex), based on costs obtained from equipment manufacturers and full-scale plants, and operating expenditure (opex), accounting for energy demand, sludge production and chemical cleaning costs. Results show that the amount of contingency built in to cope with changes in feedwater flow has a large impact on NPV. Deviation from a constant daily flow increases NPV as mean plant utilisation decreases. Conversely, adding a buffer tank reduces NPV, since less membrane surface is required when average plant utilisation increases. Membrane cost and lifetime is decisive in determining NPV: an increased membrane replacement interval from 5 to 10 years reduces NPV by 19%. Operation at higher SRT increases the NPV, since the reduced costs for sludge treatment are offset by correspondingly higher aeration costs at higher MLSS levels, though the analysis is very sensitive to sludge treatment costs. A higher sustainable flux demands greater membrane aeration, but the subsequent opex increase is offset by the reduced membrane area and the corresponding lower capex

Observation of an optical event horizon in a silicon-on-insulator photonic wire waveguide

We report on the first experimental observation of an optical analogue of an event horizon in integrated nanophotonic waveguides, through the reflection of a continuous wave on an intense pulse. The experiment is performed in a dispersion-engineered silicon-on-insulator waveguide. In this medium, solitons do not suffer from Raman induced self-frequency shift as in silica fibers, a feature that is interesting for potential applications of optical event horizons. As shown by simulations, this also allows the observation of multiple reflections at the same time on fundamental solitons ejected by soliton fission.SCOPUS: ar.jhttp://www.opticsexpress.org/abstract.cfm?URIinfo:eu-repo/semantics/publishe