14 research outputs found

    Epistemic policy networks in the European Union’s CBRN risk mitigation policy

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    This paper offers insights into an innovative and currently flagship approach of the European Union (EU) to the mitigation of chemical, biological, radiological, and nuclear (CBRN) risks. Building on its long-time experience in the CBRN field, the EU has incorporated methods familiar to the students of international security governance: it is establishing regional networks of experts and expertise. CBRN Centers of Excellence, as they are officially called, aim to contribute to the security and safety culture in different parts of Africa, the Middle East, South East Asia, and South East Europe, in the broadly construed CBRN area. These regional networks represent a modern form of security cooperation, which can be conceptualized as an epistemic policy networks approach. It offers flexibility to the participating states, which have different incentives to get involved. At the same, however, the paper identifies potential limitations and challenges of epistemic policy networks in this form

    Accretion and ejection in black-hole X-ray transients

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    Aims: We summarize the current observational picture of the outbursts of black-hole X-ray transients (BHTs), based on the evolution traced in a hardness-luminosity diagram (HLD), and we offer a physical interpretation. Methods: The basic ingredient in our interpretation is the Poynting-Robertson Cosmic Battery (PRCB, Contopoulos & Kazanas 1998), which provides locally the poloidal magnetic field needed for the ejection of the jet. In addition, we make two assumptions, easily justifiable. The first is that the mass-accretion rate to the black hole in a BHT outburst has a generic bell-shaped form. This is guaranteed by the observational fact that all BHTs start their outburst and end it at the quiescent state. The second assumption is that at low accretion rates the accretion flow is geometrically thick, ADAF-like, while at high accretion rates it is geometrically thin. Results: Both, at the beginning and the end of an outburst, the PRCB establishes a strong poloidal magnetic field in the ADAF-like part of the accretion flow, and this explains naturally why a jet is always present in the right part of the HLD. In the left part of the HLD, the accretion flow is in the form of a thin disk, and such a disk cannot sustain a strong poloidal magnetic filed. Thus, no jet is expected in this part of the HLD. The counterclockwise traversal of the HLD is explained as follows: the poloidal magnetic field in the ADAF forces the flow to remain ADAF and the source to move upwards in the HLD rather than to turn left. Thus, the history of the system determines the counterclockwise traversal of the HLD. As a result, no BHT is expected to ever traverse the entire HLD curve in the clockwise direction. Conclusions: We offer a physical interpretation of accretion and ejection in BHTs with only one parameter, the mass transfer rate.Comment: Accepted for publication in A&

    Eumicetoma de grãos pretos por Madurella grisea: registro de dois casos Eumycotic mycetoma of black grains caused by Madurella grisea: report of two cases

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    Os Autores registram dois casos de eumicetoma de grãos pretos, com localização podal, procedentes da Bahia, provocados por Madurella grisea Mackinnon et al., 1949. São estudadas a estrutura dos grãos, bem como as características micromorfológicas do fungo em vida saprofítica. Acreditam os Autores que estas observações correspondem ao sétimo e oitavo casos registrados na literatura do país, provocadas por este fungo. Os Autores consideram nomen dubium ou nomina confusa as seguintes espécies de Madurella: M. ramiroi, M. oswaldoi, M. bovoi, M. tozeuri, M. mansonii, M. brumpti, M. reynieri, M. americana, M. lackawanna e M. ikedae, o mesmo ocorrendo com a chamada Rubromadurella mycetomi. As únicas espécies válidas são Madurella mycetomatis McGinnis, 1980 (=Madurella mycetomi Brumpt, 1905) e Madurella grisea Mackinnon et al., 1949. Nos dois casos registrados o tratamento com itraconazol, por um período de 3 meses não fez regredir as lesões, havendo ligeira melhora clínica.<br>Two cases of black grains eumycotic mycetoma, occurring on a foot, are reported. Both proceeded from the State of Bahia (Brazil), and in both the etiologic agent was Madurella grisea Mackinnon et al., 1949. The grains structure as well as the micromorphologic characteristics of the fungus in saprophytic life were studied. It is the Author's belief that these observations correspond to the 7th and 8th cases reported in the Brazilian medical literature. The Authors do consider the following Madurella species as nomen dubium or nomina confusa: M. ramiroi, M. oswaldoi, M. bovoi, M. tozeuri, M. mansonii, M. brumpti, M. reynieri, M. americana, M. lackawanna e M. ikedae and the same for Rubromadurella mycetomi. The only valid species must be Madurella mycetomatis McGinnis, 1980 (=Madurella mycetomi Brumpt, 1905) and Madurella grisea Mackinnon et al., 1949. Treatment with itraconazole in both reported cases, for a 3 month duration, did not produce any regression of the lesions, the clinical improvement being meager
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