171 research outputs found

    A magnetic field diagnostic for sonoluminescence

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    This study is motivated by the extraordinary process of single bubble sonoluminescence (SBSL), where an acoustically driven spherical shock is thought to power the emitted radiation. We propose new experiments using an external magnetic field which can induce anisotropies in both the shock propagation and radiation pattern. The effects will depend on the temperature, conductivity, and size of the radiating region. Our predictions suggest that such a laboratory experiment could serve as an important diagnostic in placing bounds on these parameters and understanding the physics of sonoluminescence.Comment: Latex File, Two .eps files, 5 pages, submitted to PR

    Health Product Risk Communication: Is the message getting through?

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    Risk communication is an important component of improving the health and safety of Canadians. For numerous departments and agencies at all levels of government, as well as public and private organizations, effective risk communication can protect Canadians from preventable hazards. The Minister of Health, on behalf of Health Canada (the Sponsor), asked the Council of Canadian Academies (the Council) to provide an evidence-based and authoritative assessment of the state of knowledge on measurement and evaluation of health risk communication. This assessment focuses on identifying tools, evaluation methods, gaps in the literature, and barriers and facilitators to carrying out successful communication and evaluation activities. Specifically, this assessment examines the following questions: How can the effectiveness of health risk communications be measured and evaluated? • What types of instruments/tools are currently available for health risk communication? • What methodological best practices can be used to evaluate the reach, use and benefit of health risk communication? • What research could be done to inform the measurement of the effectiveness of risk communications? • What are the existing barriers to effective risk communications and what best practices exist to address these challenges? To address the charge, the Council assembled a multi-disciplinary panel of 11 experts (the Panel) from Canada and abroad. The Panel’s composition reflected a balance of expertise, experience, and demonstrated leadership in academic, clinical, and regulatory fields. Each member served as an informed individual, rather than as a representative of a particular discipline, patron, organization, or region

    Development of strategies for effective communication of food risks and benefits across Europe: Design and conceptual framework of the FoodRisC project

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    The FoodRisC project is funded under the Seventh Framework Programme (CORDIS FP7) of the European Commission; Grant agreement no.: 245124. Copyright @ 2011 Barnett et al.BACKGROUND: European consumers are faced with a myriad of food related risk and benefit information and it is regularly left up to the consumer to interpret these, often conflicting, pieces of information as a coherent message. This conflict is especially apparent in times of food crises and can have major public health implications. Scientific results and risk assessments cannot always be easily communicated into simple guidelines and advice that non-scientists like the public or the media can easily understand especially when there is conflicting, uncertain or complex information about a particular food or aspects thereof. The need for improved strategies and tools for communication about food risks and benefits is therefore paramount. The FoodRisC project ("Food Risk Communication - Perceptions and communication of food risks/benefits across Europe: development of effective communication strategies") aims to address this issue. The FoodRisC project will examine consumer perceptions and investigate how people acquire and use information in food domains in order to develop targeted strategies for food communication across Europe.METHODS/DESIGN: This project consists of 6 research work packages which, using qualitative and quantitative methodologies, are focused on development of a framework for investigating food risk/benefit issues across Europe, exploration of the role of new and traditional media in food communication and testing of the framework in order to develop evidence based communication strategies and tools. The main outcome of the FoodRisC project will be a toolkit to enable coherent communication of food risk/benefit messages in Europe. The toolkit will integrate theoretical models and new measurement paradigms as well as building on social marketing approaches around consumer segmentation. Use of the toolkit and guides will assist policy makers, food authorities and other end users in developing common approaches to communicating coherent messages to consumers in Europe.DISCUSSION: The FoodRisC project offers a unique approach to the investigation of food risk/benefit communication. The effective spread of food risk/benefit information will assist initiatives aimed at reducing the burden of food-related illness and disease, reducing the economic impact of food crises and ensuring that confidence in safe and nutritious food is fostered and maintained in Europe.This article is available through the Brunel Open Access Publishing Fund

    The Hidden Curriculum of Veterinary Education: Mediators and Moderators of Its Effects

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    The “hidden curriculum” has long been supposed to have an effect on students' learning during their clinical education, and in particular in shaping their ideas of what it means to be a professional. Despite this, there has been little evidence linking specific changes in professional attitudes to the individual components of the hidden curriculum. This study aimed to recognize those components that led to a change in students' professional attitudes at a UK veterinary school, as well as to identify the attitudes most affected. Observations were made of 11 student groups across five clinical rotations, followed by semi-structured interviews with 23 students at the end of their rotation experience. Data were combined and analyzed thematically, taking both an inductive and deductive approach. Views about the importance of technical competence and communication skills were promoted as a result of students' interaction with the hidden curriculum, and tensions were revealed in relation to their attitudes toward compassion and empathy, autonomy and responsibility, and lifestyle ethic. The assessment processes of rotations and the clinical service organization served to communicate the messages of the hidden curriculum, bringing about changes in student professional attitudes, while student-selected role models and the student rotation groups moderated the effects of these influences

    HIF2α reduces growth rate but promotes angiogenesis in a mouse model of neuroblastoma

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    <p>Abstract</p> <p>Background</p> <p>HIF2α/EPAS1 is a hypoxia-inducible transcription factor involved in catecholamine homeostasis, vascular remodelling, physiological angiogenesis and adipogenesis. It is overexpressed in many cancerous tissues, but its exact role in tumour progression remains to be clarified.</p> <p>Methods</p> <p>In order to better establish its function in tumourigenesis and tumour angiogenesis, we have stably transfected mouse neuroblastoma N1E-115 cells with the native form of HIF2α or with its dominant negative mutant, HIF2α (1–485) and studied their phenotype <it>in vitro </it>and <it>in vivo</it>.</p> <p>Results</p> <p><it>In vitro </it>studies reveal that HIF2α induces neuroblastoma cells hypertrophy and decreases their proliferation rate, while its inactivation by the HIF2α (1–485) mutant leads to a reduced cell size, associated with an accelerated proliferation. However, our <it>in vivo </it>experiments show that subcutaneous injection of cells overexpressing HIF2α into syngenic mice, leads to the formation of tumour nodules that grow slower than controls, but that are well structured and highly vascularized. In contrast, HIF2α (1–485)-expressing neuroblastomas grow fast, but are poorly vascularized and quickly tend to extended necrosis.</p> <p>Conclusion</p> <p>Together, our data reveal an unexpected combination between an antiproliferative and a pro-angiogenic function of HIF2α that actually seems to be favourable to the establishment of neuroblastomas <it>in vivo</it>.</p

    EMMPRIN Promotes Melanoma Cells Malignant Properties through a HIF-2alpha Mediated Up-Regulation of VEGF-Receptor-2

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    EMMPRIN's expression in melanoma tissue was reported to be predictive of poor prognosis. Here we demonstrate that EMMPRIN up-regulated VEGF receptor-2 (VEGFR-2) in two different primary melanoma cell lines and consequently increased migration and proliferation of these cells while inhibiting their apoptosis. SiRNA inhibition of VEGFR-2 expression abrogated these EMMPRIN effects. EMMPRIN regulation of VEGFR-2 was mediated through the over-expression of HIF-2α and its translocation to the nucleus where it forms heterodimers with HIF-1β. These results were supported by an in vivo correlation between the expression of EMMPRIN with that of VEGFR-2 in human melanoma tissues as well as with the extent of HIF-2α localization in the nucleus. They demonstrate a novel mechanism by which EMMPRIN promotes tumor progression through HIF-2α/VEGFR-2 mediated mechanism, with an autocrine role in melanoma cell malignancy. The inhibition of EMMPRIN in cancer may thus simultaneously target both the VEGFR-2/VEGF system and the matrix degrading proteases to block tumor cell growth and invasion

    The Action Mechanism of the Myc Inhibitor Termed Omomyc May Give Clues on How to Target Myc for Cancer Therapy

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    Recent evidence points to Myc – a multifaceted bHLHZip transcription factor deregulated in the majority of human cancers – as a priority target for therapy. How to target Myc is less clear, given its involvement in a variety of key functions in healthy cells. Here we report on the action mechanism of the Myc interfering molecule termed Omomyc, which demonstrated astounding therapeutic efficacy in transgenic mouse cancer models in vivo. Omomyc action is different from the one that can be obtained by gene knockout or RNA interference, approaches designed to block all functions of a gene product. This molecule – instead – appears to cause an edge-specific perturbation that destroys some protein interactions of the Myc node and keeps others intact, with the result of reshaping the Myc transcriptome. Omomyc selectively targets Myc protein interactions: it binds c- and N-Myc, Max and Miz-1, but does not bind Mad or select HLH proteins. Specifically, it prevents Myc binding to promoter E-boxes and transactivation of target genes while retaining Miz-1 dependent binding to promoters and transrepression. This is accompanied by broad epigenetic changes such as decreased acetylation and increased methylation at H3 lysine 9. In the presence of Omomyc, the Myc interactome is channeled to repression and its activity appears to switch from a pro-oncogenic to a tumor suppressive one. Given the extraordinary therapeutic impact of Omomyc in animal models, these data suggest that successfully targeting Myc for cancer therapy might require a similar twofold action, in order to prevent Myc/Max binding to E-boxes and, at the same time, keep repressing genes that would be repressed by Myc
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