4,424 research outputs found

    Plasma-tail activity and the interplanetary medium at Halley's Comet during Armada Week: 6-14 March 1986

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    The encounters of five spacecraft with Halley's Comet during 6-14 March 1986 offered a unique opportunity to calibrate the solar-wind interaction with cometary plasmas as recorded by remote wide-field and narrow-field/narrowband imaging. Perhaps not generally recognized in the comet community is the additional opportunity offered by the Halley Armada to study the structure of the solar-wind and interplanetary magnetic field (IMF) in three dimensions using five sets of data obtained over similar time intervals and heliocentric distances, but at somewhat different heliolatitudes. In fact, the two problems, i.e., comet physics and the structure of the interplanetary medium, are coupled if one wants to understand what conditions pertained at the comet between the encounters. This relationship is discussed

    Broadband Records of Earthquakes in Deep Gold Mines and a Comparison with Results from SAFOD, California

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    For one week during September 2007, we deployed a temporary network of field recorders and accelerometers at four sites within two deep, seismically active mines. The ground-motion data, recorded at 200 samples/sec, are well suited to determining source and ground-motion parameters for the mining-induced earthquakes within and adjacent to our network. Four earthquakes with magnitudes close to 2 were recorded with high signal/noise at all four sites. Analysis of seismic moments and peak velocities, in conjunction with the results of laboratory stick-slip friction experiments, were used to estimate source processes that are key to understanding source physics and to assessing underground seismic hazard. The maximum displacements on the rupture surfaces can be estimated from the parameter Rv, where v is the peak ground velocity at a given recording site, and R is the hypocentral distance. For each earthquake, the maximum slip and seismic moment can be combined with results from laboratory friction experiments to estimate the maximum slip rate within the rupture zone. Analysis of the four M 2 earthquakes recorded during our deployment and one of special interest recorded by the in-mine seismic network in 2004 revealed maximum slips ranging from 4 to 27 mm and maximum slip rates from 1.1 to 6:3 m=sec. Applying the same analyses to an M 2.1 earthquake within a cluster of repeating earthquakes near the San Andreas Fault Observatory at Depth site, California, yielded similar results for maximum slip and slip rate, 14 mm and 4:0 m=sec

    The BTC40 Survey for Quasars at 4.8 < z < 6

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    The BTC40 Survey for high-redshift quasars is a multicolor search using images obtained with the Big Throughput Camera (BTC) on the CTIO 4-m telescope in V, I, and z filters to search for quasars at redshifts of 4.8 < z < 6. The survey covers 40 sq. deg. in B, V, & I and 36 sq. deg. in z. Limiting magnitudes (3 sigma) reach to V = 24.6, I = 22.9 and z = 22.9. We used the (V-I) vs. (I-z) two-color diagram to select high-redshift quasar candidates from the objects classified as point sources in the imaging data. Follow-up spectroscopy with the AAT and CTIO 4-m telescopes of candidates having I < 21.5 has yielded two quasars with redshifts of z = 4.6 and z = 4.8 as well as four emission line galaxies with z = 0.6. Fainter candidates have been identified down to I = 22 for future spectroscopy on 8-m class telescopes.Comment: 27 pages, 8 figures; Accepted for publication in the Astronomical Journa

    Dissociative tendencies, sensory processing sensitivity and aberrant salience as predictors of anomalous experiences and paranormal attributions.

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    An online survey completed by 307 adults was undertaken to examine the relationship between the reporting of parapsychological experiences and three psychological dimensions, namely dissociative tendencies, sensory-processing sensitivity and aberrant salience. In contrast with most previous studies of parapsychological experiences, cognizance was taken of a distinction between a proneness to have anomalous experiences and a proneness to attribute such experiences to paranormal factors. All three psychological predictors were found to be related both to a proneness to anomalous experiences and to a proneness to paranormal attributions. Possible implications of these findings for the basis of parapsychological experiences are indicated

    Conditions for the spectrum associated with a leaky wire to contain the interval [− α2/4, ∞)

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    The method of singular sequences is used to provide a simple and, in some respects, a more general proof of a known spectral result for leaky wires. The method introduces a new concept of asymptotic straightness

    Cricket, migration and diasporic communities

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    Ever since different communities began processes of global migration, sport has been an integral feature in how we conceptualise and experience the notion of being part of a diaspora. Sport provides diasporic communities with a powerful means for creating transnational ties, but also shapes ideas of their ethnic and racial identities. In spite of this, theories of diaspora have been applied sparingly to sporting discourses. Due mainly to its central role in spreading dominant white racial narratives within the British Empire, and the various ways different ethnic groups have ‘played’ with the meanings and associations of the sport in the (post-)colonial period, cricket is an interesting focus for academic research. Despite W.G. Grace’s claim that cricket advances civilisation by promoting a common bond, binding together peoples of vastly different backgrounds, to this day cricket operates strict symbolic boundaries; defining those who do, and equally, do not belong. C.L.R. James’ now famous metaphor of looking ‘beyond the boundary’ captures the belief that, to fully understand the significance of cricket, and the sport’s roles in changing and shaping society, one must consider the wider social and political contexts within which the game is played. The collection of papers in this special issue does just that. Cricket acts as the point of departure in each, but the way in which ideas of power, representation and inequality are ‘played out’ is unique in each

    Mental representations of the supernatural: A cluster analysis of religiosity, spirituality and paranormal belief

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    The aim of the study was to establish a new typology of belief in the supernatural; categorising people, based on their levels of religiosity, spirituality and paranormal belief. Examining how the various beliefs are defined was a further objective. The reasons for people having different levels of these beliefs were discussed, highlighting ‘Metaphysical Chauvinism’ as a possible explanation. Previous research that used variousmethods to measure religiosity, spirituality and paranormal belief were discussed. Participants (n = 307) completed an online survey consisting of the revised Religious Life Inventory (rRLI), the Intrinsic Spirituality Scale (ISS) and the revised Paranormal Belief Scale (rPBS). Two cluster analyses were performed: one on the three main scales and a secondary analysis on the ISS, the subscales of the rRLI and the rPBS. The results revealed a four cluster solution for each analysis. For the main analysis the clusters were ‘believers’, ‘paranormal believers’, ‘sceptics’ and ‘religious believers’. Metaphysical Chauvinism was supported; however, it was acknowledged that there still appears to be a lack of consensus when defining supernatural beliefs. It is proposed that the cluster analysis approach is more effective than a simple scale when trying establish how a person believes
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