475 research outputs found

    Quantized reduction as a tensor product

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    Symplectic reduction is reinterpreted as the composition of arrows in the category of integrable Poisson manifolds, whose arrows are isomorphism classes of dual pairs, with symplectic groupoids as units. Morita equivalence of Poisson manifolds amounts to isomorphism of objects in this category. This description paves the way for the quantization of the classical reduction procedure, which is based on the formal analogy between dual pairs of Poisson manifolds and Hilbert bimodules over C*-algebras, as well as with correspondences between von Neumann algebras. Further analogies are drawn with categories of groupoids (of algebraic, measured, Lie, and symplectic type). In all cases, the arrows are isomorphism classes of appropriate bimodules, and their composition may be seen as a tensor product. Hence in suitable categories reduction is simply composition of arrows, and Morita equivalence is isomorphism of objects.Comment: 44 pages, categorical interpretation adde

    Hungary and the European Union: the political implications of societal security promotion

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    Hungary's constitutional commitment to support kin-nationals beyond its borders (nation policy) has been a central feature of its post-1989 foreign policy and highlights a particularly important national security concern—the societal security of national identity, culture, language and tradition. This article examines Hungary's societal security concerns and the policy methods it utilises, including its EU membership and the promotion of minority rights at the European level, to help combat these concerns. It is suggested that Hungary has found it somewhat difficult to balance its societal security policy objective with internal economic demands on its welfare system and its external foreign policy objective to maintain good neighbourly relations. This article also notes that Hungary's attempts to Europeanise, or rather 'EU-ise', minority and ethnic rights issues as a means to enhance societal security for the Hungarian nation has certain political consequences for the EU. This suggests that societal security provision is an issue that cannot be overlooked when trying to understand the longer-term implications of EU eastern enlargement

    Targeted knock-down of miR21 primary transcripts using snoMEN vectors induces apoptosis in human cancer cell lines

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    We have previously reported an antisense technology, 'snoMEN vectors', for targeted knock-down of protein coding mRNAs using human snoRNAs manipulated to contain short regions of sequence complementarity with the mRNA target. Here we characterise the use of snoMEN vectors to target the knock-down of micro RNA primary transcripts. We document the specific knock-down of miR21 in HeLa cells using plasmid vectors expressing miR21-targeted snoMEN RNAs and show this induces apoptosis. Knock-down is dependent on the presence of complementary sequences in the snoMEN vector and the induction of apoptosis can be suppressed by over-expression of miR21. Furthermore, we have also developed lentiviral vectors for delivery of snoMEN RNAs and show this increases the efficiency of vector transduction in many human cell lines that are difficult to transfect with plasmid vectors. Transduction of lentiviral vectors expressing snoMEN targeted to pri-miR21 induces apoptosis in human lung adenocarcinoma cells, which express high levels of miR21, but not in human primary cells. We show that snoMEN-mediated suppression of miRNA expression is prevented by siRNA knock-down of Ago2, but not by knock-down of Ago1 or Upf1. snoMEN RNAs colocalise with Ago2 in cell nuclei and nucleoli and can be co-immunoprecipitated from nuclear extracts by antibodies specific for Ago2

    From 3D landscape visualization to environmental simulation: The contribution of sound to the perception of virtual environments

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    This research investigated the perceptual interaction of combining sound with 3D landscape visualizations. Images sourced from Google Earth at St. James’s Park, London, UK, showing terrain only,terrain with built form or terrain with primarily vegetation were paired with four sound conditions using recordings from the park (i.e. ‘no sound’, anthropogenic, mechanical and natural). Perceived realism and preference were evaluated using a survey delivered via the Internet and in a controlled laboratory environment (N = 199 total). Analysis using repeated measures ANOVA indicated the interaction of sound and 3D visualizations significantly alters environmental perception both positively and negatively. Sounds and visuals that are congruent receive higher realism and preference ratings while the more incongruent the combination is, the lower the corresponding ratings. The lowest realism and preference ratings are given to visualizations showing terrain only combined with speech. The highest realism ratings overall correspond to visualization with built form combined with speech, and visualizations showing primarily vegetation paired with a birdcall. The absolute highest realism rating was for the visualization with primarily vegetation and some built form paired with speech, while the highest preference ratings correspond to visualizations showing vegetation paired with birdcall or no sound. Aural-visual data collected via the web-based survey was comparable to data collected in the laboratory and overall realism ratings for the Google Earth visualizations were low (e.g. below 3 on a 1–5 likert type scale). The results suggest there is an opportunity to increase experiential authenticity of 3D landscape visualizations with sound

    Transforming growth factor-β and breast cancer: Lessons learned from genetically altered mouse models

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    Transforming growth factor (TGF)-βs are plausible candidate tumor suppressors in the breast. They also have oncogenic activities under certain circumstances, however. Genetically altered mouse models provide powerful tools to analyze the complexities of TGF-βaction in the context of the whole animal. Overexpression of TGF-β can suppress tumorigenesis in the mammary gland, raising the possibility that use of pharmacologic agents to enhance TGF-β function locally might be an effective method for the chemoprevention of breast cancer. Conversely, loss of TGF-β response increases spontaneous and induced tumorigenesis in the mammary gland. This confirms that endogenous TGF-βs have tumor suppressor activity in the mammary gland, and suggests that the loss of TGF-β receptors seen in some human breast hyperplasias may play a causal role in tumor development

    Testing the Integral Model of treatment motivation in outpatients with severe mental illness

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    The current study tested the Integral Model of treatment motivation (IM) in a sample of 294 outpatients with severe mental illness, using structural equation modelling. The obtained structural model was not consistent with original theory, nor was the model invariant across time and patient groups (psychotic disorders and personality disorders). The patient’s perceived suitability of treatment, perceived costs of treatment and outcome expectancy were most strongly associated with motivation and treatment engagement. The model explained between 22 and 86% of variance in clinical outcomes, depending on the timing of the assessment. Currently, the IM does not constitute a robust framework for patterns through which patients become motivated to engage in treatment, but does explain substantial amounts of variance in clinical outcomes. The future potential of IM as a basis for interventions in the mental health care is discussed, including suggestions for subsequent research and potential alterations of the IM to improve its utility for application in clinical practice
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