Clostridium difficile outbreaks: Prevention and treatment strategies

The incidence and severity of Clostridium difficile infection (CDI) have increased dramatically over the past decade. Its treatment, however, has largely remained the same with the exception of oral vancomycin use as a first-line agent in severe disease. From 1999 to 2004, 20,642 deaths were attributed to CDI in the United States, almost 7 times the rate of all other intestinal infections combined. Worldwide, several major CDI outbreaks have occurred, and many of these were associated with the NAP1 strain. This ‘epidemic’ strain has contributed to the rising incidence and mortality of CDI. The purpose of this article is to review the current management, treatment, infection control, and prevention strategies that are needed to combat this increasingly morbid disease

In situ characterisation and manipulation of biological systems with Chi.Bio

The precision and repeatability of in vivo biological studies is predicated upon methods for isolating a targeted subsystem from external sources of noise and variability. However, in many experimental frameworks, this is made challenging by nonstatic environments during host cell growth, as well as variability introduced by manual sampling and measurement protocols. To address these challenges, we developed Chi.Bio, a parallelised open-source platform that represents a new experimental paradigm in which all measurement and control actions can be applied to a bulk culture in situ. In addition to continuous-culturing capabilities, it incorporates tunable light outputs, spectrometry, and advanced automation features. We demonstrate its application to studies of cell growth and biofilm formation, automated in silico control of optogenetic systems, and readout of multiple orthogonal fluorescent proteins in situ. By integrating precise measurement and actuation hardware into a single low-cost platform, Chi.Bio facilitates novel experimental methods for synthetic, systems, and evolutionary biology and broadens access to cutting-edge research capabilities

Predicting the effect of changes to the urban environment on future electrical demand using building simulation and archetype models

Future urban electrical loads are of interest to a range of stakeholders from utilities to network planners. In this paper, a pragmatic approach to the modelling of urban electrical demands using archetype models and simulated building demand profiles is described. The profiles can be scaled, transformed and combined to produce time-series electrical loads for multiple buildings connected to a substation in a distribution network. The modelling approach has been verified against measured demand data. Possible changes in future peak urban electrical demand were quantified for a sample of substations in Glasgow, UK, using four future demand scenarios. The picture emerging was complex, with peak demand increasing in some cases where electric vehicles and electrified heating combine. However, there were many situations where a combination of improved energy efficiency and microgeneration lead to reduced peak demand

Automatic detection of ionospheric Alfvén Resonances using signal and image processing techniques

Ionospheric Alfvén Resonances (IAR) are a type of ELF wave phenomenon in the 0.5-10 Hz frequency range and are detectable in magnetic field variations as measured by induction coil magnetometers. They are believed to be excited by electric fields from lightning strikes leaking from the troposphere into the ionosphere, causing the oscillation of magnetic field lines through the upper atmosphere. In September 2012, the British Geological Survey installed two orthogonal coils in Eskdalemuir in the Scottish Borders. The coils reliably record variations of the magnetic field in the frequency band from 0.1 - 100 Hz in the north-south and east-west components. IAR appear in the data almost on a daily basis. Investigation of the IAR events in the induction coil data show that they appear as a series of fringes in spectrograms (i.e. plots of power at time versus frequency) between 0.5 and 7 Hz, occasionally extending beyond the first Schumann resonance to 10 Hz. They typically appear after the onset of local night time, expanding in frequency width until midnight and fading a few hours before local dawn. There are usually between five and fifteen fringes. Their appearance varies with season – occurring most often in northern hemisphere winter. Given the complexity of the analysis and the volume of data, a new protocol for detecting and classifying key parameters was developed using image and signal processing techniques. In the first instance, individual spectra for time-series of 100 seconds are analysed for peak power in the frequencies between 0.5 and 10 Hz. Hence the frequency for each IAR is determined (i.e. the signal processing part). This generates an image of ‘spot’ frequencies for each IAR for each day. Next, a series of image processing filters are applied to the ‘spot’ images to connect the IAR occurrences together in a coherent manner. No manual intervention is required. The method picks out the IAR across an entire day of data, allowing statistics related to frequency (f), peak-to-peak frequency (∆f) and number of peaks etc. to be automatically determined from the entire dataset. We show the details and examples of the new method and the results from the first eighteen months of data

Expanding the substrates for a bacterial hydrogenlyase reaction

Escherichia coli produces enzymes dedicated to hydrogen metabolism under anaerobic conditions. In particular, a formate hydrogenlyase (FHL) enzyme is responsible for the majority of hydrogen gas produced under fermentative conditions. FHL comprises a formate dehydrogenase (encoded by fdhF) linked directly to [NiFe]-hydrogenase-3 (Hyd-3), and formate is the only natural substrate known for proton reduction by this hydrogenase. In this work, the possibility of engineering an alternative electron donor for hydrogen production has been explored. Rational design and genetic engineering led to the construction of a fusion between Thermotoga maritima ferredoxin (Fd) and Hyd-3. The Fd-Hyd-3 fusion was found to evolve hydrogen when co-produced with T. maritima pyruvate :: ferredoxin oxidoreductase (PFOR), which links pyruvate oxidation to the reduction of ferredoxin. Analysis of the key organic acids produced during fermentation suggested that the PFOR/Fd-Hyd-3 fusion system successfully diverted pyruvate onto a new pathway towards hydrogen production

Brian Boydell: Mosaics and Sketches

Brian Boydell (1917-2000) Mosaics & Sketches: Chamber Music for Harp Mosaics and Sketches explores the Irish composer Brian Boydell’s chamber music for harp written over two decades, 1960-1980. In this recording, Cliona Doris performs Boydell’s solo work for pedal harp, A Pack of Fancies for a Travelling Harper and is joined by TU Dublin Conservatoire colleagues in three chamber works: Four Sketches for Two Irish Harps, Five Mosaics for Violin and Harp, and Quintet for Flute, Harp and String Trio. The recording was funded through a research grant from Technological University Dublin. The support of RTÉ lyric fm and the Contemporary Music Centre for this recording is gratefully acknowledged

GIC at mid-latitudes under extreme Dst scenarios

The Dst index is primarily a measure of the magnitude of the equatorial magnetospheric ring current, based on an hourly average of the variation of the Horizontal (H) component from a number of low and mid-latitude ground-based observatories. Extreme values of this index are rare; for example the largest in recent decades occurred during the March 1989 storm, with Dst peaking at -589 nT. Larger values of Dst have been established for the Carrington event – in September 1859 the Bombay observatory recorded a peak of about -850 nT. However, some researchers have suggested that Dst may have been even larger still (-1760 nT), based on one value from Bombay during the 1859 storm. More recent theoretical work has suggested that -2500 nT is the largest possible value physically achievable, given our knowledge of the magnetosphere. Although the ring current variation affects low to mid-latitudes directly, at higher latitudes most variation of H is due to auroral electrojet activity. Motivated by the largest theoretical possible Dst value, we investigate the size of the H variation at high latitudes that might occur during large Dst excursions, by extrapolating relationships observed between H and Dst from previous large storms. To test the consequence of these large H variations we compute the likely GIC in mid-latitude European high-voltage power distribution networks, based on a set of conductivity and grid models of similar complexity, during geomagnetic storms with Dst values of -800, -1700 and -2500 nT