14,856 research outputs found

    Modelling uncertainties for measurements of the H → γγ Channel with the ATLAS Detector at the LHC

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    The Higgs boson to diphoton (H → γγ) branching ratio is only 0.227 %, but this final state has yielded some of the most precise measurements of the particle. As measurements of the Higgs boson become increasingly precise, greater import is placed on the factors that constitute the uncertainty. Reducing the effects of these uncertainties requires an understanding of their causes. The research presented in this thesis aims to illuminate how uncertainties on simulation modelling are determined and proffers novel techniques in deriving them. The upgrade of the FastCaloSim tool is described, used for simulating events in the ATLAS calorimeter at a rate far exceeding the nominal detector simulation, Geant4. The integration of a method that allows the toolbox to emulate the accordion geometry of the liquid argon calorimeters is detailed. This tool allows for the production of larger samples while using significantly fewer computing resources. A measurement of the total Higgs boson production cross-section multiplied by the diphoton branching ratio (σ × Bγγ) is presented, where this value was determined to be (σ × Bγγ)obs = 127 ± 7 (stat.) ± 7 (syst.) fb, within agreement with the Standard Model prediction. The signal and background shape modelling is described, and the contribution of the background modelling uncertainty to the total uncertainty ranges from 18–2.4 %, depending on the Higgs boson production mechanism. A method for estimating the number of events in a Monte Carlo background sample required to model the shape is detailed. It was found that the size of the nominal γγ background events sample required a multiplicative increase by a factor of 3.60 to adequately model the background with a confidence level of 68 %, or a factor of 7.20 for a confidence level of 95 %. Based on this estimate, 0.5 billion additional simulated events were produced, substantially reducing the background modelling uncertainty. A technique is detailed for emulating the effects of Monte Carlo event generator differences using multivariate reweighting. The technique is used to estimate the event generator uncertainty on the signal modelling of tHqb events, improving the reliability of estimating the tHqb production cross-section. Then this multivariate reweighting technique is used to estimate the generator modelling uncertainties on background V γγ samples for the first time. The estimated uncertainties were found to be covered by the currently assumed background modelling uncertainty

    The Professional Identity of Doctors who Provide Abortions: A Sociological Investigation

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    Abortion is a medicalised problem in England and Wales, where the law places doctors at the centre of legal provision and puts doctors in control of who has an abortion. However, the sex-selection abortion scandal of 2012 presented a very real threat to 'abortion doctors', when the medical profession's values and practices were questioned in the media, society and by Members of Parliament. Doctors found themselves at the centre of a series of claims that stated doctors were acting both illegally and unethically, driven by profit rather than patient needs. Yet, the perspectives of those doctors who provide abortions has been under-researched; this thesis aims to fill that gap by examining the beliefs and values of this group of doctors. Early chapters highlight the ambiguous position of the abortion provider in Britain, where doctors are seen as a collective group of professionals motivated by medical dominance and medical autonomy. They outline how this position is then questioned and contested, with doctors being presented as unethical. By studying abortion at the macro-, meso- and micro-levels, this thesis seeks to better understand the values of the 'abortion doctor', and how these levels shape the work and experiences of abortion providers in England and Wales. This thesis thus addresses the question: 'What do abortion doctors' accounts of their professional work suggest about the contemporary dynamics of the medicalisation of abortion in Britain?'. It investigates the research question using a qualitative methodological approach: face-to-face and telephone interviews were conducted with 47 doctors who provide abortions in England and Wales. The findings from this empirical study show how doctors' values are linked to how they view the 'normalisation of abortion'. At the macro-level doctors, openly resisted the medicalisation of abortion through the position ascribed to them by the legal framework, yet at the meso-level doctors construct an identity where normalising abortion is based on further medicalising services. Finally, at the micro-level, the ambiguous position of the abortion provider is further identified in terms of being both a proud provider and a stigmatised individual. This thesis shows that while the existing medicalisation literature has some utility, it has limited explanatory power when investigating the problem of abortion. The thesis thus provides some innovative insights into the relevance and value of medicalisation through a comprehensive study on doctors' values, beliefs and practices

    Walking with the Earth: Intercultural Perspectives on Ethics of Ecological Caring

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    It is commonly believed that considering nature different from us, human beings (qua rational, cultural, religious and social actors), is detrimental to our engagement for the preservation of nature. An obvious example is animal rights, a deep concern for all living beings, including non-human living creatures, which is understandable only if we approach nature, without fearing it, as something which should remain outside of our true home. “Walking with the earth” aims at questioning any similar preconceptions in the wide sense, including allegoric-poetic contributions. We invited 14 authors from 4 continents to express all sorts of ways of saying why caring is so important, why togetherness, being-with each others, as a spiritual but also embodied ethics is important in a divided world

    The company she keeps : The social and interpersonal construction of girls same sex friendships

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    This thesis begins a critical analysis of girls' 'private' interpersonal and social relations as they are enacted within two school settings. It is the study of these marginal subordinated worlds productivity of forms of femininity which provides the main narrative of this project. I seek to understand these processes of (best) friendship construction through a feminist multi-disciplinary frame, drawing upon cultural studies, psychoanalysis and accounts of gender politics. I argue that the investments girls bring to their homosocial alliances and boundary drawing narry a psychological compulsion which is complexly connected to their own experiences within the mother/daughter bond as well as reflecting positively an immense social debt to the permissions girls have to be nurturant and ; negatively their own reproduction of oppressive exclusionary practices. Best friendship in particular gives girls therefore, the experience of 'monogamy' continuous of maternal/daughter identification, reminiscent of their positioning inside monopolistic forms of heterosexuality. But these subcultures also represent a subversive discontinuity to the public dominance of boys/teachers/adults in schools and to the ideologies and practices of heterosociality and heterosexuality. By taking seriously their transmission of the values of friendship in their chosen form of notes and diaries for example, I was able to access the means whereby they were able to resist their surveillance and control by those in power over them. I conclude by arguing that it is through a recognition of the valency of these indivisiblly positive and negative aspects to girls cultures that Equal Opportunities practitioners must begin if they are serious about their ambitions. Methods have to be made which enable girls to transfer their 'private' solidarities into the 'public' realm, which unquestionably demands contesting with them the causes and consequences of their implication in the divisions which also contaminate their lives and weaken them

    In search of 'The people of La Manche': A comparative study of funerary practices in the Transmanche region during the late Neolithic and Early Bronze Age (250BC-1500BC)

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    This research project sets out to discover whether archaeological evidence dating between 2500 BC - 1500 BC from supposed funerary contexts in Kent, flanders and north-eastern Transmanche France is sufficient to make valid comparisons between social and cultural structures on either side of the short-sea Channel region. Evidence from the beginning of the period primarily comes in the form of the widespread Beaker phenomenon. Chapter 5 shows that this class of data is abundant in Kent but quite sparse in the Continental zones - most probably because it has not survived well. This problem also affects the human depositional evidence catalogued in Chapter 6, particularly in Fanders but also in north-eastern Transmanche France. This constricts comparative analysis, however, the abundant data from Kent means that general trends are still discernible. The quality and volume of data relating to the distribution, location, morphology and use of circular monuments in all three zones is far better - as demonstrated in Chapter 7 -mostly due to extensive aerial surveying over several decades. When the datasets are taken as a whole, it becomes possible to successfully apply various forms of comparative analyses. Most remarkably, this has revealed that some monuments apparently have encoded within them a sophisticated and potentially symbolically charged geometric shape. This, along with other less contentious evidence, demonstrates a level of conformity that strongly suggests a stratum of cultural homogeneity existed throughout the Transmanche region during the period 2500 BC - 1500 BC. The fact that such changes as are apparent seem to have developed simultaneously in each of the zones adds additional weight to the theory that contact throughout the Transmanche region was endemic. Even so, it may not have been continuous; there may actually have been times of relative isolation - the data is simply too course to eliminate such a possibility

    Disunity in society, fractures at home: family relating in the context of divisive socio-political issues

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    Section A A systematic literature review conducted to identify and explore research that has investigated adult intrafamilial relationships and divisive political issues since 2016. Ten papers are included in the review. The studies are critiqued using a mixed-methods risk of bias tool. Findings are collated using narrative synthesis. The synthesis focuses on relational responses—to divisive political issues—the potential reasons for these responses, and their consequences. Review findings are discussed in relation to previous theoretical and empirical literature. Finally, clinical and research implications are presented. Section B A grounded theory study to develop an understanding of adult intrafamilial invalidation in the context of social and political change. Brexit and COVID-19 serve as the contextual lens through which the phenomenon was observed. Data from 11 participants and 45 screening questionnaire respondents were analysed as part of the study. A model of family “Rejection of You” experiences is presented outlining foundational and contextual factors that frame the experience, the experience itself, and relational, behavioural, cognitive, and emotional consequences. Findings are discussed in relation to previous theory and previous empirical research. Clinical implications are considered and possible directions for future research are set out
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