2,125 research outputs found

    Interpretation of x-ray-absorption dichroism experiments

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    A rule is derived to use x-ray magnetic circular dichroism spectra to extract the magnetic moment of the conduction-band states with j= l -1/2 separately from those with j= l + 1/2 as a function of energy. This quantity is straightforward to determine from the electronic band structure. The rule is illustrated with an application to pure iron and to the random substitutional alloy Fe_{80}CO_{20}

    Modelling mammographic microcalcification clusters using persistent mereotopology

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    AbstractIn mammographic imaging, the presence of microcalcifications, small deposits of calcium in the breast, is a primary indicator of breast cancer. However, not all microcalcifications are malignant and their distribution within the breast can be used to indicate whether clusters of microcalcifications are benign or malignant. Computer-aided diagnosis (CAD) systems can be employed to help classify such microcalcification clusters. In this paper a novel method for classifying microcalcification clusters is presented by representing discrete mereotopological relations between the individual microcalcifications over a range of scales in the form of a mereotopological barcode. This barcode based representation is able to model complex relations between multiple regions and the results on mammographic microcalcification data shows the effectiveness of this approach. Classification accuracies of 95% and 80% are achieved on the MIAS and DDSM datasets, respectively. These results are comparable to existing state-of-the art methods. This work also demonstrates that mereotopological barcodes could be used to help trained clinicians in their diagnosis by providing a clinical interpretation of barcodes that represent both benign and malignant cases

    Electronic structure and x-ray magnetic dichroism in random substitutional alloys of f-electron elements

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    The Koringa-Kohn-Rostoker —coherent-potential-approximation method combines multiple-scattering theory and the coherent-potential approximation to calculate the electronic structure of random substitutional alloys of transition metals. In this paper we describe the generalization of this theory to describe f-electron alloys. The theory is illustrated with a calculation of the electronic structure and magnetic dichroism curves for a random substitutional alloy containing rare-earth or actinide elements from first principles

    Health promotion in an Australian Aboriginal community: the Growing Strong Brains® toolkit

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    Aim: The aim of this paper is to describe the implementation and evaluation of the Growing Strong Brains® (GSB) toolkit in a remote Aboriginal community in Western Australia (WA) over a 2-year period, 2018–2019. Background: Ngala, a community service organisation in WA, developed the GSB toolkit in 2014, a culturally appropriate and interactive resource to build knowledge of early childhood development within Aboriginal communities. This was in response to evidence that a higher percentage of children in Aboriginal communities were developmentally vulnerable compared to the rest of the population. The GSB toolkit promotes awareness and understanding of early brain development pre-birth and in the early years of a child’s life. Methods: The project was underpinned by participatory action research (PAR). Reflective PAR review cycles (n = 5) monitored local community engagement, navigated challenges and utilised community strengths. Fifty-nine local service providers attended a 2-day formal training. Data were collected by using various methods throughout the project, including feedback following training, focus groups, surveys, one-on-one interviews using yarning techniques and reflective feedback from the Project Lead. Findings: Establishing local Aboriginal project staff was pivotal to the success of the project. When delivering services for and with Aboriginal people, it is essential that cultural competence, safety and decision-making is carried through from planning to implementation and evaluation, and involves genuine, respectful and authentic relationships. Sufficient time allocation directed towards building relationships with other service providers and local community members needs to be considered and built into future projects. The Growing Strong Brains® project is embedded within the local community, and anticipated implementation outcomes were achieved. The support of the local people and service providers was beyond expectation, enabling the building of local capacity, and the development of a common understanding of the key messages from the GSB toolkit to allow integration throughout all levels of the community. This project has been important to build on the strategies necessary to introduce, implement and evaluate the GSB toolkit in other remote Aboriginal communities

    Prostate cancer risk: associations with ultraviolet radiation, tyrosinase and melanocortin-1 receptor genotypes

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    Exposure to ultraviolet radiation may reduce prostate cancer risk, suggesting that polymorphism in genes that mediate host pigmentation will be associated with susceptibility to this cancer. We studied 210 prostate cancer cases and 155 controls to determine whether vitamin D receptor (VDR, Taql and Fokl variants), tyrosinase (TYR, codon 192 variant) and melanocortin-1 receptor (MC1R, Arg151Cys, Arg160Trp, Val92Met, Asp294His and Asp84Glu variants) genotypes are associated with risk. UV exposure was determined using a questionnaire. MC1R Arg160/Arg160 homozygotes were at increased risk (P = 0.027, odds ratio = 1.94) while TYR A2/A2 homozygotes were at reduced risk of prostate cancer (P = 0.033, odds ratio = 0.48). These associations remained significant after correction for UV-exposure. Stratification of cases and controls by quartiles of exposure, showed that the protective effect of TYR A1A2 (P = 0.006, odds ratio 0.075) and A2A2 (P = 0.003, odds ratio 0.055) was particularly strong in subjects who had received the greatest exposure. Our data show for the first time, that allelism in genes linked with skin pigment synthesis is associated with prostate cancer risk possibly because it mediates the protective effects of UV. Importantly, susceptibility is associated with an interaction between host predisposition and exposure. © 2001 Cancer Research Campaign  http://www.bjcancer.co

    From social contract to 'social contrick' : the depoliticisation of economic policy-making under Harold Wilson, 1974–75

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    The 1974-79 Labour Governments were elected on the basis of an agreement with the TUC promising a redistribution of income and wealth known as the Social Contract. However, the Government immediately began to marginalise these commitments in favour of preferences for incomes policy and public expenditure cuts, which has led the Social Contract to be described as the 'Social Contrick'. These changes were legitimised through a process of depoliticisation, and using an Open Marxist framework and evidence from the National Archives, the paper will show that the Treasury's exchange rate strategy and the need to secure external finance placed issues of confidence at the centre of political debate, allowing the Government to argue there was no alternative to the introduction of incomes policy and the reduction of public expenditure
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