Development of an Infection-Responsive Fluorescent Sensor for the Early Detection of Urinary Catheter Blockage

Formation of crystalline biofilms following infection by <i>Proteus mirabilis</i> can lead to encrustation and blockage of long-term indwelling catheters, with serious clinical consequences. We describe a simple sensor, placed within the catheter drainage bag, to alert of impending blockage via a urinary color change. The pH-responsive sensor is a dual-layered polymeric “lozenge”, able to release the self-quenching dye 5(6)-carboxyfluorescein in response to the alkaline urine generated by the expression of bacterial urease. Sensor performance was evaluated within a laboratory model of the catheterized urinary tract, infected with both urease positive and negative bacterial strains under conditions of established infection, achieving an average “early warning” of catheter blockage of 14.5 h. Signaling only occurred following infection with urease positive bacteria. Translation of these sensors into a clinical environment would allow appropriate intervention before the occurrence of catheter blockage, a problem for which there is currently no effective control method

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

The effect of organic farming on soil physical properties, infiltration and workability

Organically managed land has increased to 4 % of the total area of agricultural land in the UK. Changing land management can impact upon the rural environment (soils, hydrology and biodiversity) and rural community (socio-economics and culture). This thesis aims to compare the effects of organic farming practices on soil physical, chemical and hydrological properties in relation to conventional farming systems. The research combines data from three different scales: field measurements, plot measurements and catchment modelling. At the field scale: 16 pairs of farms (organic and conventional between 50 and 3000 m apart) located in England, over a range of soil textures: clayey, silty, medium and coarse were investigated. There were also two different land uses (grass and winter wheat). Data was obtained on soil properties including: shear strength, Atterberg limits, field capacity, aggregate stability, HOST values, infiltration rates and Soil Organic Carbon (SOC). The analysis of the data shows that, whilst it is possible to detect the effects of both soil texture and land use (grassland / arable) on a number of the soil properties; there is no evidence that organic farming improves soil properties or physical condition - equally there is no detrimental effect. This is in agreement with the results of a number of other European studies. There was evidence to show that infiltration rates are greater on organically managed grassland than conventional grassland; which agrees with the HOST analysis where fewer fields were degraded under organic management. Fewer traces of pesticides and herbicides were in the soil water from the organic fields compared with the conventionally managed fields; none were at a level which would contribute to agricultural pollution. Cont/D

Dataset for 'Development of an Infection-Responsive Fluorescent Sensor for the Early Detection of Urinary Catheter Blockage'

Formation of crystalline biofilms following infection by Proteus mirabilis can lead to encrustation and blockage of long-term indwelling catheters, with serious clinical consequences. We describe a simple sensor, placed within the catheter drainage bag, to alert of impending blockage via a urinary colour change. The dataset presented shows data from the characterisation and testing of the prototype sensors, Including: investigation into the fluorescent properties of 5(6)-carboxyfluorescein (CF) (fluorescence output vs CF concentration and fluorescence output vs solution pH), change in pH vs time for P. mirabilis subcultures and bacterial supernatants, corresponding dye release vs time, as well as data from the testing of the sensors within the in vitro bladder model system (change in fluorescence output within the drainage bag and approximate CF concentration with time). Investigation into the initial dye release kinetics was also undertaken and the data presented in this dataset. Standard curves at three different pHs (6,7 and 8) are presented as well as the overlaid release profiles over time.A plate reader (BMG Labtech) was used to quantify fluorescent output throughout these experiments. Basic bacterial subculturing was used from a single bacterial colony, to create subcultures. To create supernatants, overnight cultures were centrifuged at 4000 rpm for 10 minutes and the supernatant separated from the pellet.All data were processed in GraphPad Prism software. Graphs were plotted and statistical analysis (unpaired t test) were performed within the same software.Equipment: Electronic pH meter (Jenway) Plate reader (BMG fluorostar) Software: GraphPad Prism 7.02 for Window

Dataset for 'Development of an Infection-Responsive Fluorescent Sensor for the Early Detection of Urinary Catheter Blockage'

Formation of crystalline biofilms following infection by Proteus mirabilis can lead to encrustation and blockage of long-term indwelling catheters, with serious clinical consequences. We describe a simple sensor, placed within the catheter drainage bag, to alert of impending blockage via a urinary colour change. The dataset presented shows data from the characterisation and testing of the prototype sensors, Including: investigation into the fluorescent properties of 5(6)-carboxyfluorescein (CF) (fluorescence output vs CF concentration and fluorescence output vs solution pH), change in pH vs time for P. mirabilis subcultures and bacterial supernatants, corresponding dye release vs time, as well as data from the testing of the sensors within the in vitro bladder model system (change in fluorescence output within the drainage bag and approximate CF concentration with time). Investigation into the initial dye release kinetics was also undertaken and the data presented in this dataset. Standard curves at three different pHs (6,7 and 8) are presented as well as the overlaid release profiles over time

Dataset for 'Development of an Infection-Responsive Fluorescent Sensor for the Early Detection of Urinary Catheter Blockage'

Formation of crystalline biofilms following infection by Proteus mirabilis can lead to encrustation and blockage of long-term indwelling catheters, with serious clinical consequences. We describe a simple sensor, placed within the catheter drainage bag, to alert of impending blockage via a urinary colour change. The dataset presented shows data from the characterisation and testing of the prototype sensors, Including: investigation into the fluorescent properties of 5(6)-carboxyfluorescein (CF) (fluorescence output vs CF concentration and fluorescence output vs solution pH), change in pH vs time for P. mirabilis subcultures and bacterial supernatants, corresponding dye release vs time, as well as data from the testing of the sensors within the in vitro bladder model system (change in fluorescence output within the drainage bag and approximate CF concentration with time). Investigation into the initial dye release kinetics was also undertaken and the data presented in this dataset. Standard curves at three different pHs (6,7 and 8) are presented as well as the overlaid release profiles over time