Handling and communicating uncertainty in chained geospatial web services

Recent developments in service-oriented and distributed computing have created exciting opportunities for the integration of models in service chains to create the Model Web. This offers the potential for orchestrating web data and processing services, in complex chains; a flexible approach which exploits the increased access to products and tools, and the scalability offered by the Web. However, the uncertainty inherent in data and models must be quantified and communicated in an interoperable way, in order for its effects to be effectively assessed as errors propagate through complex automated model chains. We describe a proposed set of tools for handling, characterizing and communicating uncertainty in this context, and show how they can be used to 'uncertainty- enable' Web Services in a model chain. An example implementation is presented, which combines environmental and publicly-contributed data to produce estimates of sea-level air pressure, with estimates of uncertainty which incorporate the effects of model approximation as well as the uncertainty inherent in the observational and derived data.

Studies in the handling and absorption of biopterin derivatives in man

DUE TO COPYRIGHT RESTRICTIONS ONLY AVAILABLE FOR CONSULTATION AT ASTON UNIVERSITY LIBRARY AND INFORMATION SERVICES WITH PRIOR ARRANGEMENT

Handling complexity in a small engineering business. Available in 2 volumes.

DUE TO COPYRIGHT RESTRICTIONS ONLY AVAILABLE FOR CONSULTATION AT ASTON UNIVERSITY LIBRARY WITH PRIOR ARRANGEMENT

Aminoglycoside-induced changes in the renal handling of cations in the Fischer 344 rat

Disturbances of cation homeostasis, particularly hypomagnesaemia, are a frequent consequence of treatment with aminoglycoside antibiotics. These disturbances are thought to result from renal wasting of cations and administration of gentamicin to rats has been shown to produce hypercalciuria and hypermagnesiuria. The aims of this study were to attempt to elucidate these responses in anaesthetised rats infused with gentamicin and to use this model to investigate the mechanisms of these effects. Fischer 344 rats were anaesthetised and surgically prepared for clearance experiments. Infusion of gentamicin in isotonic saline increased urinary output of calcium and magnesium while sodium and potassium output were unaffected. These elevations in calcium and magnesium excretion were explained by reduced tubular reabsorption of these cations. Both the hypercalciuric and hypermagnesiuric responses to gentamicin were extremely rapid and were sustained during drug infusion; when gentamicin infusion ceased both responses were rapidly reversible. Infusion of another aminoglycoside, tobramycin, produced very similar effects to gentamicin. The hypercalciuria and hypermagnesiuria caused by gentimicin infusion were unaffected by parathyroidectomy. The peak increases in calcium and magnesium output brought about by infusion of gentamicin with frusemide were not significantly different to the increases produced by frusemide alone. The site at which gentamicin interferes with calcium and magnesium reabsorption cannot be firmly deduced from these results. However, the known close association between calcium and sodium reabsorption in the proximal tubule implies that gentamicin is unlikely to change proximal calcium reabsorption without a similar change in proximal sodium reabsorption. The similarity between the hypercalciuric and hypermagnesiuric effects of frusemide alone and the effects of frusemide infused simultaneously with gentamicin suggests that gentamicin may act at the same site as the diuretic, the thick ascending limb of the loop of Henle.

Efficacy and toxicity of biocides used in handling sterile pharmaceuticals

This thesis has sought to investigate disinfection agents and procedures which may provide sanitisation against bacterial spores. A hard-surface disinfection test method was designed to ascertain which combinations of biocide and application method were most effective against bacterial spores. A combination of spraying and wiping was the most effective method of disinfection against Bacillus spores, with wiping found to play a key role in spore removal. The most efficacious of the biocides investigated was the 6% hydrogen peroxide. Vaporised Hydrogen Peroxide (VHP) gassing was more effective than traditional disinfection. In addition to efficacy, the toxic potential of the biocides to human airway epithelial cells in vitro was evaluated. Toxicity against human bronchial and nasal epithelial cells was assessed by determining cell viability, inflammatory status, protein oxidation and epithelial cell layer integrity. In addition the cell death mechanism following biocide exposure was investigated. There was a decrease in viable cells following exposure to all biocides when applied at practical concentrations. Almost all of the biocides tested elicited a pro-inflammatory response from the cells as measured by IL-8 production. All biocides increased protein oxidation as measured by thiol and carbonyl levels. Measurement of transepithelial electrical resistance and paracellular permeability indicated biocide-dependent decrease in epithelial cell barrier function. The cellular response was biased towards necrotic rather than apoptotic death. The use of biocides, although efficacious to some effects against Bacillus spores, will require careful monitoring for adverse health effects on personnel.

Novel real-time homodyne coherent receiver using a feed-forward based carrier extraction scheme for phase modulated signals

We report a novel real-time homodyne coherent receiver based on a DPSK optical-electrical-optical (OEO) regenerator used to extract a carrier from carrier-less phase modulated signals based on feed-forward based modulation stripping. The performance of this non-DSP based coherent receiver was evaluated for 10.66Gbit/s BPSK signals. Self-homodyne coherent detection and homodyne detection with an injection-locked local oscillator laser was demonstrated. The performance was evaluated by measuring the electrical signal-to-noise (SNR) and recording the eye diagrams. Using injection-locking for the LO improves the performance and enables homodyne detection with optical injection-locking to operate with carrier-less BPSK signals without the need for polarization multiplexed pilot-tones.

Novel synchronous DPSK optical regenerator based on a feed-forward based carrier extraction scheme

We experimentally demonstrate a novel synchronous 10.66Gbit/s DPSK OEO regenerator which uses a feed-forward carrier extraction scheme with an injection-locked laser to synchronize the regenerated signal wavelength to the incoming signal wavelength. After injection-locking, a low-cost DFB laser used at the regenerator exhibited the same linewidth characteristics as the narrow line-width transmitter laser. The phase regeneration properties of the regenerator were evaluated by emulating random Gaussian phase noise applied to the DPSK signal before the regenerator using a phase modulator driven by an arbitrary waveform generator. The overall performance was evaluated in terms of electrical eye-diagrams, BER measurements, and constellation diagrams.