90 research outputs found

    Recovery phase of magnetic storms induced by different interplanetary drivers

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    Statistical analysis of Dst behaviour during recovery phase of magnetic storms induced by different types of interplanetary drivers is made on the basis of OMNI data in period 1976-2000. We study storms induced by ICMEs (including magnetic clouds (MC) and Ejecta) and both types of compressed regions: corotating interaction regions (CIR) and Sheaths. The shortest, moderate and longest durations of recovery phase are observed in ICME-, CIR-, and Sheath-induced storms, respectively. Recovery phases of strong (Dstmin<−100Dst_{min} < -100 nT) magnetic storms are well approximated by hyperbolic functions Dst(t)=a/(1+t/τh)Dst(t)= a/(1+t/\tau_h) with constant τh\tau_h times for all types of drivers while for moderate (−100<Dstmin<−50-100 < Dst_{min} < -50 nT) storms DstDst profile can not be approximated by hyperbolic function with constant τh\tau_h because hyperbolic time τh\tau_h increases with increasing time of recovery phase. Relation between duration and value DstminDst_{min} for storms induced by ICME and Sheath has 2 parts: DstminDst_{min} and duration correlate at small durations while they anticorrelate at large durations.Comment: 18 pages, 4 figures, 2 tables, submitted to JGR special issue "Response of Geospace to High-Speed Streams

    Geoeffectiveness and efficiency of CIR, Sheath and ICME in generation of magnetic storms

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    We investigate relative role of various types of solar wind streams in generation of magnetic storms. On the basis of the OMNI data of interplanetary measurements for the period of 1976-2000 we analyze 798 geomagnetic storms with Dst < -50 nT and their interplanetary sources: corotating interaction regions (CIR), interplanetary CME (ICME) including magnetic clouds (MC) and Ejecta and compression regions Sheath before both types of ICME. For various types of solar wind we study following relative characteristics: occurrence rate; mass, momentum, energy and magnetic fluxes; probability of generation of magnetic storm (geoeffectiveness) and efficiency of process of this generation. Obtained results show that despite magnetic clouds have lower occurrence rate and lower efficiency than CIR and Sheath they play an essential role in generation of magnetic storms due to higher geoeffectiveness of storm generation (i.e higher probability to contain large and long-term southward IMF Bz component).Comment: 23 pages, 4 figures, 3 tables, submitted to JGR special issue "Response of Geospace to High-Speed Streams

    A discursive approach to narrative accounts of hearing voices and recovery

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    Substantive objective: To research the range of discursive constructions ‘recovered’ voice hearers employ to describe hearing voices and the implications for positioning and subjectivity (what can be thought and felt) using each construction. Methodological objective and method: To explore a ‘sympathetic’ application of Foucauldian discourse analysis, adapting Willig’s (2008 Willig, C. 2008. Introducing Qualitative Research in Psychology, Maidenhead: Open University Press. ) method, analysing two published accounts. Results and conclusions: Heterogeneous discursive constructions for talking about hearing voices were identified, including: ‘many-’selves’’, ‘taking-the-lead-in-your-own-recovery’, ‘voices-as-an-’imagined-world’’ and ‘voices-as-a-coping-strategy-for-dealing-with-trauma’. The discourse of the biomedical model was not prominent, suggesting alternate discursive constructions may create subjects with a greater capacity for ‘living with voices’ and create a subjectivity from which vantage point the experience holds meaning and value and can be integrated into life experiences. This research may have useful clinical applications for mental health services aiming to collaboratively explore service users’ ways of understanding hearing voices

    Biogeochemical signatures in the lichen Hypogymnia physodes in the mid Urals

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    Abstract Multi-element content and uranium (U) isotopes were investigated in the lichen Hypogymnia physodes (native and transplants) sampled across a 60-km transect, centred on Karabash smelter town, from Turgoyak Lake (SW) to Kyshtym (NE) to investigate the origin of U. Kyshtym was the site of a major nuclear accident in 1957. 234 U/ 238 U activity ratios in native thalli sampled during July 2001 were within the natural isotopic ratio in minerals. Uranium/thorium (U/Th) ratios were higher in native thalli towards the NE (average 0.73) than those in the SW (average 0.57). Element signatures in native thalli and transplants suggest U was derived from fossil fuel combustion from Karabash and sources lying further to the east. Systematic and significant U enrichment indicative of a nuclear fuel cycle source was not detected in any sample. Element signatures in epiphytic lichen transplants and native thalli provide a powerful method to evaluate U deposition

    The Importance of Social Support Structures for Retention and Success

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    As a policy goal, widening participation is increasingly associated with retention and completion. For those who are concerned with equity or social mobility, it makes little sense to recruit new types of student if they do not then qualify for a graduate profession. There has been growing interest in retention and completion among researchers and policymakers, with much attention&nbsp;centring on the extent to which new students can be helped to integrate into the institution. Drawing on a study of undergraduates in the UK, this chapter explores the extent to which student support services and wider informal support networks feature in students' narratives of retention. Conceptually, we are interested here in the ways in which students feel themselves to be legitimate members of the &lsquo;imagined community' of higher education, a concept that we have adapted from Anderson's treatment of nationalisms (Anderson, 1991)

    Ensembl 2008.

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    The Ensembl project (http://www.ensembl.org) is a comprehensive genome information system featuring an integrated set of genome annotation, databases and other information for chordate and selected model organism and disease vector genomes. As of release 47 (October 2007), Ensembl fully supports 35 species, with preliminary support for six additional species. New species in the past year include platypus and horse. Major additions and improvements to Ensembl since our previous report include extensive support for functional genomics data in the form of a specialized functional genomics database, genome-wide maps of protein-DNA interactions and the Ensembl regulatory build; support for customization of the Ensembl web interface through the addition of user accounts and user groups; and increased support for genome resequencing. We have also introduced new comparative genomics-based data mining options and report on the continued development of our software infrastructure
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