3,408 research outputs found

    Weighted Dirac combs with pure point diffraction

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    A class of translation bounded complex measures, which have the form of weighted Dirac combs, on locally compact Abelian groups is investigated. Given such a Dirac comb, we are interested in its diffraction spectrum which emerges as the Fourier transform of the autocorrelation measure. We present a sufficient set of conditions to ensure that the diffraction measure is a pure point measure. Simultaneously, we establish a natural link to the theory of the cut and project formalism and to the theory of almost periodic measures. Our conditions are general enough to cover the known theory of model sets, but also to include examples such as the visible lattice points.Comment: 44 pages; several corrections and improvement

    Individual Rights, Economic Transactions, and Recognition: A Legal Approach to Social Economics

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    Modernity brought the idea of individual property rights as a com- plex phenomenon. However, economics adopted a simplistic view of property as a fundamental institution, understating the complex interaction of different rights and obligations that frame the legal environment of economic processes with an insufficiently elaborated tool. Here, a more elaborate view of legal elements will be propose

    The Preliminary Examination of Organics in the Returned Stardust Samples from Comet Wild 2

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    The primary objective of STARDUST is to collect coma samples from comet 8lP/Wild 2. These samples were collected by impact onto aerogel tiles on Jan 2, 2004 when the spacecraft flew through the comet's coma at a relative velocity of about 6.1 km/sec. Measurements of dust impacts on the front of the spacecraft suggest that the aerogel particle collector was impacted by 2800 +/- 500 particles larger than 15 micron in diameter. Following recovery of the Sample Return Capsule (SRC) on Jan 15, 2006, the aerogel collector trays will be removed in a clean room at JSC. After documentation of the collection, selected aerogel tiles will be removed and aerogel and cometary samples will be extracted for study. A number of different extraction techniques will be used, each optimized for the analytical technique that is to be used. The STARDUST Mission will carry out a 6 month preliminary examination (PE) of a small portion of the returned samples. The examination of the samples will be made by a number of subteams that will concentrate on specific aspects of the samples. One of these is the Organics PE Team (see the author list above for team members). These team members will use a number of analytical techniques to produce a preliminary characterization of the abundance and nature of the organics (if any) in the returned samples

    Discourse and identity in a corpus of lesbian erotica

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    This article uses corpus linguistic methodologies to explore representations of lesbian desires and identities in a corpus of lesbian erotica from the 1980s and 1990s. We provide a critical examination of the ways in which “lesbian gender,” power, and desire are represented, (re-)produced, and enacted, often in ways that challenge hegemonic discourses of gender and sexuality. By examining word frequencies and collocations, we critically analyze some of the themes, processes, and patterns of representation in the texts. Although rooted in linguistics, we hope this article provides an accessible, interdisciplinary, and timely contribution toward developing understandings of discursive practices surrounding gender and sexuality

    A pilot randomised double blind controlled trial of the efficacy of purified fatty acids for the treatment of women with endometriosis-associated pain (PurFECT):study protocol

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    Abstract Background Endometriosis affects 6–10% of women and is associated with debilitating pelvic pain. It costs the UK > £2.8 billion per year in loss of productivity. Endometriosis can be managed by surgical excision or medically by ovarian suppression. However, ~ 75% symptoms recur after surgery and available medical treatments have undesirable side effects and are contraceptive. Omega-3 purified fatty acids (PUFA) have been shown in animal models to reduce factors that are thought to lead to endometriosis-associated pain, have minimal side effects, and no effects on fertility. This paper presents a protocol for a two-arm, pilot parallel randomised controlled trial (RCT) which aims to inform the planning of a future multicentre trial to evaluate the efficacy of Omega-3 PUFA in the management of endometriosis-associated pain in women. Methods The study will recruit women with endometriosis over a 12-month period in the National Health Service (NHS) Lothian, UK, and randomise them to 8 weeks of treatment with Omega-3 PUFA or comparator (olive oil). The primary objective is to assess recruitment and retention rates. The secondary objectives are to determine the effectiveness/acceptability to participants of the proposed methods of recruitment/randomisation/treatments/questionnaires, to inform the sample size calculation and to refine the research methodology for a future large randomised controlled trial. Response to treatment will be monitored by pain scores and questionnaires assessing physical and emotional function compared at baseline and 8 weeks. Discussion We recognise that there may be potential difficulties in mounting a large randomised controlled trial for endometriosis to assess Omega-3 PUFA because they are a dietary supplement readily available over the counter and already used by women with endometriosis. We have therefore designed this pilot study to assess practical feasibility and following the ‘Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials’ recommendations for the design of chronic pain trials. Trial registration ISRCTN4420234

    Social Work and Pornography:some ethical considerations

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    On the back of recent high-profile cases, the subject of internet pornography has become the focus of media and political attention. Social workers are increasingly likely to be drawn into this issue through requirements to provide courts with reports or taking child protection decisions relating to clients' use of child or, potentially, extreme pornography. Within a risk paradigm, they may look for answers based on technical and ‘scientific’ knowledge. We argue here that pornography is, first and foremost, an ethical issue. This article offers a preliminary exploration of some of the ethical issues it raises. We take as a starting point that whatever we might personally think about it, pornography is a fact of everyday life. Yet, in the current political and social climate it has become deeply moralised. We argue that social workers might legitimately adopt a range of value positions in relation to pornography that these need to be opened up to ethical debate

    STUDENTS' PERCEPTIONS OF THE INCIDENCE OF BURN-OUT AMONG THEIR TEACHERS

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    research paperThe aim was to explore students' perceptions of teacher burn-out in relation to the incidence of disruptive student classroom behaviour and teachers' competence to cope with it. A random sample of students from a Regional Training Centre participated. First, it was shown that the Maslach Burnout Inventory, the Coping with Disruptive Behaviour Scale and the Perceived Disruptive Behaviour Scale could be adapted for students to report symptoms of burn-out perceived among their teachers, the occurrence of perceived disruptive student behaviour and the students' perception of their teachers' ability to cope with such behaviour. Second, students' perceptions do not differ according to their age. Third, a significant difference was found between the perceptions of male and female students in respect of emotional exhaustion and depersonalisation, but not in respect of personal achievement. Finally, a considerable percentage of variance on each of the three burn-out dimensions is explained by teachers' ability to cope with student disruptive behaviour and perceived disruptive student behaviour. Students' perceptions of their teachers appear to contribute valid information on the mental health of the latter. It is advisable for future research into teacher burn-out to be based both on the teachers' self-reports and on the students' reports
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