2,802 research outputs found

    Magnetic fluctuation and cosmic ray diurnal variations

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    A unified theory of cosmic ray diurnal variations has been proposed in which the first 3 harmonics of the cosmic ray daily variation all results from a single anisotropy produced by the combined effects of adiabatic focusing and anisotropic pitch angle scattering. The theoretical description of steady state cosmic ray anisotropies are simplified and improved. Preliminary results of a study of correlations between cosmic ray diurnal variations and the fluctuation characteristics of the interplanetary magnetic field are presented and discussed in light of the theory

    Exponential anisotropy of solar cosmic rays

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    On 16 February 1984 a flare on the Sun's invisible disk produced a large, highly anisotropic solar particle event. A technique, in which interplanetary scattering parameters are determined purely from the form of the particle anisotropy, is applied to energetic particle data from neutron monitors and the ICE spacecraft

    Isotropic intensity waves and features of their occurrence

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    Waves of daily average cosmic ray intensity, dependent on interplanetary magnetic fields (IMF) polarity, have been observed in 1982 (Jacklyn and Pomerantz, 1983) and again in 1983 and 1984. These waves at first appeared to be due to the North-South anisotropy. Further investigation revealed that the waves comprise two components, a large isotropic and a smaller anisotropic component. The anisotropic part is attributed to the North-South anisotropy and is in phase with the larger isotropic component in the Southern Hemisphere. Unlike the North-South anisotropy which is a permanent feature of cosmic ray modulation, the isotropic phenomenon appears to be episodic in character. When present, it is clearly dependent on IMF polarity but does not correlate well with IMF field strength. It is conjectured that the phenomenon might indicate some difference between the intensity regimes above and below the neutral sheet

    Analysis of proton and electron spectrometer data from OGO-5 spacecraft

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    The interaction between the geomagnetic and interplanetary magnetic fields is studied through its effects upon the intensities of solar electrons reaching the polar caps during times of strongly anisotropic electron fluxes in the magnetosheath. During the particle event of November 18, 1968, electrons of solar origin were observed outside the magnetopause with detectors aboard OGO-5. Correlative studies of these satellite observations and concurrent measurements by riometers and ionospheric forward scatter systems in both polar regions revealed that the initial stage of the associated polar cap absorption event is attributable to the arrival of solar electrons. Evidence of a north-south asymmetry in the solar electron flux, at a time when the interplanetary magnetic field vector was nearly parallel with the ecliptic plane, supports an open magnetospheric model. The analysis indicates that an anisotropic electron flux may be isotropized at the magnetopause before propagating into the polar regions

    Acceleration Of Protons To Above 6 MeV Using H2O >Snow> Nanowire Targets

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    A scheme is presented for using H2O >snow> nanowire targets for the generation of fast protons. This novel method may relax the requirements for very high laser intensities, thus reducing the size and cost of laser based ion acceleration system.Physic

    Negotiation of entitlement in proposal sequences

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    Meetings are complex institutional events at which participants recurrently negotiate institutional roles, which are oriented to, renegotiated, and sometimes challenged. With a view to gaining further understanding of the ongoing negotiation of roles at meetings, this article examines one specific recurring feature of meetings: the act of proposing future action. Based on microanalysis of video recordings of two-party strategy meetings, the study shows that participants orient to at least two aspects when making proposals: 1) the acceptance or rejection of the proposal; and 2) questions of entitlement: who is entitled to launch a proposal, and who is entitled to accept or reject it? The study argues that there is a close interrelation between questions of entitlement, aligning and affiliating moves, and the negotiation of institutional roles. The multimodal analysis also reveals the use of various embodied practices by participants for the local negotiation of entitlement and institutional roles

    Transcriptional tools: Small molecules for modulating CBP KIX-dependent transcriptional activators

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    Previously it was demonstrated that amphipathic isoxazolidines are able to functionally replace the transcriptional activation domains of endogenous transcriptional activators. In addition, in vitro binding studies suggested that a key binding partner of these molecules is the CREB Binding Protein (CBP), more specifically the KIX domain within this protein. Here we show that CBP plays an essential role in the ability of isoxazolidine transcriptional activation domains to activate transcription in cells. Consistent with this model, isoxazolidines are able to function as competitive inhibitors of the activators MLL and Jun, both of which utilize a binding interaction with KIX to up-regulate transcription. Further, modification of the N2 side chain produced three analogs with enhanced potency against Jun-mediated transcription, although increased cytotoxicity was also observed. Collectively these small KIX-binding molecules will be useful tools for dissecting the role of the KIX domain in a variety of pathological processes. © 2010 Wiley Periodicals, Inc. Biopolymers 95: 17–23, 2011.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78234/1/21548_ftp.pd
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