Study of the kaon contribution to the T2K neutrino beam using neutrino interactions in the Near Detector

T2K is a long-baseline neutrino oscillation experiment. It uses an accelerator- produced neutrino beam, whereby a beam of protons impinges on a nuclear target, producing kaon and pion mesons that decay to neutrinos. The main neutrino detectors are situated at 2.50 off-axis from the centre of the beam. An accurate flux prediction for this off-axis beam is crucial to achieve the sensitivity required for the goals of T2K. External experiments reduce the major flux uncertainty (hadronic interactions in the target), but are inherently independent of the real and variable beamline conditions of T2K. Therefore, in situ measurements are required to validate the flux. This thesis uses data from the T2K near detector (ND280) to validate the ux prediction. The normalisation of K+-originating neutrinos at the ND280 is measured. The K+ beam component is important since K+ daughters dominate the high energy part of the μ beam and contribute to the intrinsic e contamination. As many aspects of the beam simulation affect this measurement, including the hadron production at the target and the off-axis angle, it is used to validate the entire system. The November 2010 to March 2011 data set is used, corresponding to 7:837 x 1019 protons on target. μ charged-current interactions are selected (with 86.3% purity) using the ND280 tracker and binned according to the momentum and angle of the muon candidate. The Monte Carlo (MC) is fitted to the data to extract the normalisations of both K+ and π+ originating neutrinos, bK and bπ respectively. The flux, cross-section and detector systematic errors are considered. The best fit point is at bK = 0:86 and bπ = 0:78, consistent with the nominal MC at the 1σ level. Additionally, results of the first time calibration of the ND280 detector, primarily of the ECal sub-detector, are presented

Installation and Commissioning of the CMS Level-1 Calorimeter Trigger Upgrade

The Compact Muon Solenoid (CMS) experiment is currently installing upgrades to their Calorimeter Trigger for LHC Run 2 to ensure that the trigger thresholds can stay low, and physics data collection will not be compromised. The electronics will be upgraded in two stages. Stage-1 for 2015 will upgrade some electronics and links from copper to optical in the existing calorimeter trigger so that the algorithms can be improved and we do not lose valuable data before stage-2 can be fully installed by 2016. Stage-2 will fully replace the calorimeter trigger at CMS with a micro-TCA and optical link system. It requires that the updates to the calorimeter back-ends, the source of the trigger primitives, be completed. The new systemâ??s boards will utilize Xilinx Virtex-7 FPGAs and have hundreds of high-speed links operating at up to 10 Gbps to maximize data throughput. The integration, commissioning, and installation of stage-1 in 2015 will be described, as well as the integration and parallel installation of the stage-2 in 2015, for a fully upgraded CMS calorimeter trigger in operation by 2016.Solenoid (CMS) experiment is currently installing an upgrade to their Calorimeter Trigger to ensure that the trigger thresholds can stay low, and physics data collection will not be compromised by these challenging conditions. The electronics will be upgraded in two stages. Stage-1 will upgrade some electronics and links from copper to optical in the existing calorimeter trigger so that the algorithms can be improved and we do not lose valuable data before Stage-2 can be fully installed. Stage-2 will fully replace the calorimeter trigger at CMS with a micro-TCA and optical link system, and require that the updates to the calorimeter back-ends, the source of the trigger primitives, are completed. The new systemâ??s boards will utilize Xilinx Virtex 7 FPGAs and have hundreds of high-speed links operating at up to 10 Gbps to maximize data throughput. The integration, commissioning, and installation of stage-1 in 2015 will be described, as well as the integration and parallel installation of the stage-2 in 2015, for an fully upgraded CMS calorimeter trigger in operation by 2016

Prophylactic biological mesh reinforcement versus standard closure of stoma site (ROCSS): a multicentre, randomised controlled trial

Background: Closure of an abdominal stoma, a common elective operation, is associated with frequent complications; one of the commonest and impactful is incisional hernia formation. We aimed to investigate whether biological mesh (collagen tissue matrix) can safely reduce the incidence of incisional hernias at the stoma closure site. Methods: In this randomised controlled trial (ROCSS) done in 37 hospitals across three European countries (35 UK, one Denmark, one Netherlands), patients aged 18 years or older undergoing elective ileostomy or colostomy closure were randomly assigned using a computer-based algorithm in a 1:1 ratio to either biological mesh reinforcement or closure with sutures alone (control). Training in the novel technique was standardised across hospitals. Patients and outcome assessors were masked to treatment allocation. The primary outcome measure was occurrence of clinically detectable hernia 2 years after randomisation (intention to treat). A sample size of 790 patients was required to identify a 40% reduction (25% to 15%), with 90% power (15% drop-out rate). This study is registered with ClinicalTrials.gov, NCT02238964. Findings: Between Nov 28, 2012, and Nov 11, 2015, of 1286 screened patients, 790 were randomly assigned. 394 (50%) patients were randomly assigned to mesh closure and 396 (50%) to standard closure. In the mesh group, 373 (95%) of 394 patients successfully received mesh and in the control group, three patients received mesh. The clinically detectable hernia rate, the primary outcome, at 2 years was 12% (39 of 323) in the mesh group and 20% (64 of 327) in the control group (adjusted relative risk [RR] 0·62, 95% CI 0·43–0·90; p=0·012). In 455 patients for whom 1 year postoperative CT scans were available, there was a lower radiologically defined hernia rate in mesh versus control groups (20 [9%] of 229 vs 47 [21%] of 226, adjusted RR 0·42, 95% CI 0·26–0·69; p<0·001). There was also a reduction in symptomatic hernia (16%, 52 of 329 vs 19%, 64 of 331; adjusted relative risk 0·83, 0·60–1·16; p=0·29) and surgical reintervention (12%, 42 of 344 vs 16%, 54 of 346: adjusted relative risk 0·78, 0·54–1·13; p=0·19) at 2 years, but this result did not reach statistical significance. No significant differences were seen in wound infection rate, seroma rate, quality of life, pain scores, or serious adverse events. Interpretation: Reinforcement of the abdominal wall with a biological mesh at the time of stoma closure reduced clinically detectable incisional hernia within 24 months of surgery and with an acceptable safety profile. The results of this study support the use of biological mesh in stoma closure site reinforcement to reduce the early formation of incisional hernias. Funding: National Institute for Health Research Research for Patient Benefit and Allergan