Experimental, computational and analytical studies of slug flow.

Imperial Users onl

One does not simply tweet without consequence: a study of the electoral contest in Ashgrove

Twitter is now a fixture of society, an online meeting place for people to air their grievances about human rights and civil liberty, discuss global warming, stalk celebrities and show off their cats. An unedited forum of comments that is a gold mine of free data for those who seek to monitor opinions on everything from mobile phone providers to voting preferences. It is now unusual for modern political candidates not to sustain a social media presence during their campaign in order to connect with their constituency. This study examines Twitter use by candidates in a single electorate—the seat of Ashgrove—during an election campaign in the Australian state of Queensland in March 2012. In particular, it looks at how Twitter user groups drive concept discussions around themes and concepts within the campaign, thereby exerting influence within the domain as part of the election process. Using a theory building approach, the data set made up of 35,000 tweets was analysed using text analytics software to reveal how Twitter can be used as a feedback mechanism for candidates, how user groups drive concept discussions on Twitter, the role of legacy media within this framework, and how the language of Twitter is a unique genre of communication

Comparing predictive performance of near infrared spectroscopy at a field, regional, national and continental scales by using spiking and data mining techniques

The development of accurate visible and near infrared (vis-NIR) spectroscopy calibration models for selected soil properties is a crucial step for variable rate application in precision agriculture. The objective of the present study was to compare the prediction performance of vis-NIR spectroscopy at local, regional, national and continental scales using data mining techniques including spiking. Fresh soil samples collected from farms in the UK, Czech Republic, Germany, Denmark and the Netherlands were scanned with a fibre-type vis-NIR spectrophotometer (tec5 Technology for Spectroscopy, Germany), with a spectral range of 305-2200 nm. After dividing spectra into calibration (75%) and validation (25%) sets, spectra in the calibration set were subjected to three multivariate calibration models. The partial least squares regression (PLSR), multivariate adaptive regression splines (MARS) and support vector machines (SVM), with leave-one-out cross-validation were used to establish calibration models of total nitrogen (TN), total carbon (TC) and soil moisture content (MC). The results showed the lowest model performance to be obtained when the single field (local scale) data were used in the calibration models. The effect of spiking was significant and the best model performance was obtained when local samples collected from two fields in the UK were spiked with European soil samples (continental), followed by when the same samples were spiked with UK samples (national). Therefore, these results suggest that continental and national vis-NIR calibration models can be successfully used to predict TN, TC and MC. Therefore, selection of the optimal soil samples with the appropriate data mining technique should be considered when developing vis-NIR calibration models for a non-standard soil to cover a wide variation range

Paediatric drowning: a standard operating procedure to aid the prehospital management of paediatric cardiac arrest resulting from submersion

Objectives: Drowning is one of the leading causes of death in children. Resuscitating a child following submersion is a highpressure situation, and standard operating procedures can reduce error. Currently, the Resuscitation Council UK guidance does not include a standard operating procedure on paediatric drowning. The objective of this project was to design a standard operating procedure to improve outcomes of drowned children. Methods: A literature review on the management of paediatric drowning was conducted. Relevant publications were used to develop a standard operating procedure for management of paediatric drowning. Results: A concise standard operating procedure was developed for resuscitation following paediatric submersion. Specific recommendations include: the Heimlich manoeuvre should not be used in this context; however, prolonged resuscitation and therapeutic hypothermia are recommended. Conclusions: This standard operating procedure is a potentially useful adjunct to the Resuscitation Council UK guidance and should be considered for incorporation into its next iteration

The effects of irradiation on the biological and biomechanical properties of an acellular porcine superflexor tendon graft for cruciate ligament repair

Acellular xenogeneic tissues have the potential to provide ‘off‐the‐shelf’ grafts for anterior cruciate ligament (ACL) repair. To ensure that such grafts are sterile following packaging, it is desirable to use terminal sterilization methods. Here, the effects of gamma and electron beam irradiation on the biological and biomechanical properties of a previously developed acellular porcine superflexor tendon (pSFT) were investigated. Irradiation following treatment with peracetic acid was compared to peracetic acid treatment alone and the stability of grafts following long‐term storage assessed. Irradiation did not affect total collagen content or biocompatibility (determined using a contact cytotoxicity assay) of the grafts, but slightly increased the amount of denatured collagen in and decreased the thermal denaturation temperature of the tissue in a dose dependant fashion. Biomechanical properties of the grafts were altered by irradiation (reduced ultimate tensile strength and Young's modulus, increased failure strain), but remained superior to reported properties of the native human ACL. Long term storage at 4°C had no negative effects on the grafts. Of all the conditions tested, a dose of minimum 25 kGy of gamma irradiation had least effect on the grafts, suggesting that this dose produces a biocompatible pSFT graft with adequate mechanical properties for ACL repair

AtSPX1 affects the AtPHR1 -DNA binding equilibrium by binding monomeric AtPHR1 in solution

Phosphorus is an essential macronutrient for plant growth, and is deficient in about 50% of agricultural soils. The transcription factor Phosphate Starvation Response 1 (PHR1) plays a central role in regulating the expression of a subset of Phosphate Starvation Induced (PSI) genes through binding to a cis acting DNA element termed P1BS. In Arabidopsis and rice, activity of AtPHR1/OsPHR2 is regulated in part by their downstream target SPX proteins through protein-protein interaction. Here we provide kinetic and affinity data for interaction between AtPHR1 and P1BS sites. Using SPR, a tandem P1BS sequence showed ~50-fold higher affinity for MBPAtdPHR1 (a fusion protein comprising the DNA binding domain and coiled-coiled domain of AtPHR1 fused to maltose binding protein) than a single site. The affinity difference was largely reflected in a much slower dissociation rate from the 2x P1BS binding site, suggesting an important role for protein cooperativity. Injection of AtSPX1 in the presence of phosphate or inositol hexakisphosphate (InsP6) failed to alter the MBPAtdPHR1-P1BS dissociation rate, while pre-mixing of these two proteins in the presence of either 5 mM Pi or 500 µM InsP6 resulted in a much lower DNA binding signal from MBPAtdPHR1. These data suggest that in the Pi restored condition, AtSPX1 can bind to monomeric AtPHR1 in solution and therefore regulate PSI gene expression by tuning the AtPHR1-DNA binding equilibrium. This Pi-dependent regulation of AtPHR1-DNA binding equilibrium also generates a negative feedback loop on the expression of AtSPX1 itself, providing a tight control of PSI gene expression