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Development of a new Soft Muon Tagger for the Identification of b quarks, applied to a Top Quark Pair Production Cross Section Measurement, using the ATLAS Detector at CERN.
Get PDFThis thesis presents a study of a method for identifying b-jets by searching for “soft” muons produced within them. This method, a so-called Soft Muon Tagger, uses the quality of the match (Χ2match) between tracks left in the inner detector and the muon systems within the ATLAS detector to discriminate between muons within hadronic jets produced by the decay of b quarks, and those within light flavour jets.
The complete characteristics of the tagger are investigated in a detailed study on simulated data. The scale factors between the efficiency of the tagger in simulated and collision data, dependent on the kinematics of the tagged muon, are found using J/Ψ decays. These are used in a measurement of the top quark pair production cross section in collision data.
The measurement is performed on data taken during the 2011 run of the LHC, specifically in the lepton+jets top-antitop quark decay channel. A summary of this measurement is presented, and is found to be compatible with theoretical predictions for the cross section at a centre of mass energy of √s = 7 TeV, and with published ATLAS and CMS measurements using b-tagging in the lepton+jets channel. The measured cross section is:
σtt ̄ = 165 ± 2(stat.) ± 17(syst.) ± 3(lumi.) pb
The Χ2match-based soft muon tagger contributes a small b-tagging systematic uncertainty to the cross section measurement compared to measurements performed using lifetime based b-taggers, and has a good signal to background ratio
Effects of Tree Species Diversity on Insect Herbivory
Get PDFIt is generally believed that tree species growing in mixed forest stands are less susceptible to insect herbivore damage than if grown in monocultures, but previous studies have been largely observational and focussed mainly on tree species richness effects. In this thesis, I examined effects of three components of forest diversity (tree species richness, intraspecific genotypic diversity and functional diversity) on insect herbivores using three long-term forest diversity experiments in Finland and Germany. I have also explored the sources of variation in and the mechanisms behind the effects of tree diversity on insect herbivores. I found that all three components of forest diversity significantly influenced insect herbivore abundance and damage. Tree species richness effects depended on the insect herbivore feeding guild, but also changed within season and between years. As a result, silver birch (Betula pendula) experienced both associational resistance (reduced damage in mixed stands) and associational susceptibility (higher damage in mixed stands) to different insect herbivores and in some instances this altered temporally. In contrast, tree species richness effects on insect herbivory were spatially consistent and not mediated by tree size (physical apparency), physical properties of leaves or natural enemies. Interestingly, tree species richness and genotypic diversity had opposite effects on leaf miners; leaf miner abundance and species richness were lower in species-rich stands, but higher in mixtures containing several genotypes of silver birch. To test the effects of tree functional diversity, I created a functional diversity index based on constitutive emissions of monoterpenes and isoprene by different tree species and showed that tree species which emitted low levels of volatiles experienced associational resistance in stands with high diversity of volatile emissions. This suggests that increasing chemical complexity in mixed stands may interfere with host finding ability of herbivores
Understanding the role of b2b social and relational factors on web-based EDI adoption: A collaborative approach in the container liner shipping industry
Get PDFOrganisations today operate in a complex, unpredictable, globalised, and competitive business environment and challenging marketplace, emphasis on just-in-time deliveries and service quality through the integration of resources. In response to the changing business dynamics, web-based EDI (WEDI) has been adopted by the global container shipping industry to cost-effectively utilise available resources to build and remain its competitive advantage. To improve the current understanding of WEDI adoption factors, this research explores inter-organisational collaboration of WEDI adoption, focusing on the organisational adoption stage and examine how business level social and relational factors influence WEDI adoption in the context of the container liner shipping industry.
Based on theoretical and literature reviews on previous EDI adoption, in particular to three key inter-organisational system adoption empirical research (including Lee and Lim, 2005; Boonstra and de Vries, 2005; Zhu et al., 2006), an integrated research model was established of which features ‘Social Resources’ of (trading partner power, trading partner dependence and social network effect), ‘Relational Resources’ of (trading partner trust, top management commitment and guanxi, ‘Reward’ of (perceived interests), and ‘Technological State’ of (technological trust and e-readiness) as prominent antecedents.
Through E-mail and Web Survey approach, we examine the nine independent constructs in the research model quantitatively on a dataset of 164 respondents from the top 20 leading container shipping liner in year 2009 and 195 respondents of the top 20 leading container shipping liner in 2012 by 3 case studies through online surveys. After examining its reliability, validity and correlation of the constructs, PLS structural Equation Modelling was applied to test hypotheses.
The empirical results update how firms exchange business dada, in particular to the use of WEDI in the industry. This study demonstrated that ‘Social Resources’ of trading partner power, trust and guanxi, positively associated with the perceived interest of WEDI adoption. Relational Resources’ of trading partner trust, top management commitment and guanxi positively associated with the perceived interest of WEDI adoption. It also confirms the nine constructs to be positively association the WEDI adoption decisions. Drawing upon social exchange theory, we argue that firms simultaneously modify and adjust their social and relational resources to affect other firms’ expected benefit as a reward.
Overall, based on a rigorous empirical analysis of two different international dataset, this research provides valuable and the most updated insights into a set of key factors that influence WEDI adoption. By recognising what may influence WEDI adoption in the context of the container liner shipping, this study will be useful in suggesting strategies to overcome the constraints that inhibit adoption. Researchers will benefit from the study's theoretical insights and explore further WEDI adoption and diffusion patterns. Practitioners who learn why organisations adopt WEDI and what the related factors are that influence the adoption process will make better strategic decisions concerning the adoption of WEDI
A Secure and Trusted Channel Protocol for User Centric Smart Cards
No full textThe User Centric Smart Card Ownership Model (UCOM) provides an open and dynamic smart card environment enabling cardholders to request installation/deletion of an application to which they are entitled. As in this model, smart cards are not under the control of a centralised authority; hence, it is difficult for an application provider to ascertain their trustworthiness. At present, proposed secure channel protocols for the smart card environment do not provide adequate assurance required by the UCOM. In this paper, we explore the reasons behind their failure to meet the UCOM requirements and then propose a secure and trusted channel protocol that meets them. In addition, the proposed protocol is also suitable to GlobalPlatform's consumer-centric smart cards. A comparison of the proposed protocol with existing smart card and selected Internet protocols is provided. Then we analyse the protocol with the CasperFDR tool. Finally, we detail the implementation and the performance measurement
Clostridium difficile: Infection and Immunity
No full textClostridium difficile is a Gram positive pathogen of significant importance in the UK, Europe and the USA. No vaccine has been developed and current treatments are focused on hospital management and the use of antibiotics. The disease is spread in hospitals in the spore form and the role of spores in C. difficile infecton is poorly understood. In this project spores of C. difficile have been characterised. The proteins from the outermost layers of the spore were identified and the genes cloned. Three of these surface proteins have unique enzymatic properties that maybe important for symptoms of disease. The ability of C. difficile spores to adhere to intestinal cells was found to be far greater than with live cells and through this we have identified that the spore may play an important role in colonisation. The regulation of spore coat gene expression during sporulation was also examined and temporal phases of genes expression identified. A major part of this project was to develop a mucosal vaccine to C. difficile. The approach used was to clone the C-terminus of toxin A onto the surface of Bacillus subtilis spores and use these recombinant spores to immunise mice and hamsters. We found that oral delivery of these spores conferred 75% protection to C. difficile infection in a hamster model of infection. Further, parenteral immunisation of the same antigens (toxin A and B) failed to generate mucosal responses and this showed that mucosal immunisation is critical for good protection. Finally, we found that antibodies to the C-terminus of toxin A were cross reactive to the C-terminus of toxin B. This showed that mucosal delivery of just the C-terminus of toxin A is sufficient to confer protection in an animal model of infection. The outcome of this work is that we have shown the parameters for successful immunisation and vaccination against C. difficile
The Royal Academy of Arts Audio Project
No full textThe Royal Academy Audio Project
Overview
The Royal Academy Audio Project (RAAP) is an on-going practical research project, sponsored by The Contemporary Circle on behalf of the Royal Academy of Art Library.
Aims
The primary purpose of this project is to record a series of interviews with leading Royal Academicians, concentrating on their professional career, and their relationship with the Royal Academy of Art.
Many of the most influential artists of the 20th Century are now of an advanced age and whilst some have been interviewed in the past, many have not – certainly not in a considered and rigorous manner. This project will seek to address that before it is too late. The Library have identified upwards of seventy Royal Academicians that they believe should be included. It is anticipated that RAAP will look to record twelve subjects per year.
Outcomes
The bulk of the material is intended for archive within the Royal Academy of Art library as primary source material for researchers and academics.
1. The completely unedited recordings – the non-mediated audio texts.
2. The ‘Umm & Ah’ Edit – removal of the hesitations and repetitions of all interviews.
3. The 45 Minute Documentary – the mediated text intended as a potentially ‘commercial’ and ‘engaging’ output for educated but uninformed listeners (based on the BBC Reithian precept).
4. Transcription texts of all the interviews (post ‘Umm & Ah’ edit)
Production Breakdown
Interview 1: The artist in his/her studio or workspace
Interview 2: The artist in the sound studio at Royal Holloway
Interview 3: With another RA artist commenting upon the work of the subject.
Interview 4: A recorded conversation between the subject and the commenting artist.
The Radio Documentary – constructed from all the interviews
Personnel
Rhys Davies – Editor (archive) Producer & Studio Presenter (Documentary)
Dr Jean Wainwright – Researcher and Interviewer.
rhysdavies201
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