2,860 research outputs found
Magnetic fluctuation and cosmic ray diurnal variations
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
Isotropic intensity waves and features of their occurrence
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
Exponential anisotropy of solar cosmic rays
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
Analysis of proton and electron spectrometer data from OGO-5 spacecraft
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
Utilization of woody browse by White-tailed Deer (Odocoileus virginianus) in Valley Forge National Park
Acceleration Of Protons To Above 6 MeV Using H2O >Snow> Nanowire Targets
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
PIH34 The Impact Of Private Versus Public Insurance On Health Status, Work Productivity And Health Care Utilization For Individuals Residing In Brazil
Negotiation of entitlement in proposal sequences
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
CARD11 mediates factor-specific activation of NF-ÎșB by the T cell receptor complex
NFâÎșB is a critical target of signaling downstream of the T cell receptor (TCR) complex, but how TCR signaling activates NFâÎșB is poorly understood. We have developed an expression cloning strategy that can identify catalytic and noncatalytic molecules that participate in different pathways of NFâÎșB activation. Screening of a mouse thymus cDNA library yielded CARD11, a membraneâassociated guanylate kinase (MAGUK) family member containing CARD, PDZ, SH3 and GUK domains. Using a CARDâdeleted variant of CARD11 and RNA interference (RNAi), we demonstrate that CARD11 mediates NFâÎșB activation by αCD3/αCD28 crossâlinking and PMA/ionomycin treatment, but not by TNFα or dsRNA. CARD11 is not required for TCRâmediated induction of NFAT or APâ1. CARD11 functions upstream of the IÎșBâkinase (IKK) complex and cooperates with Bcl10 in a CARD domainâdependent manner. RNAiârescue experiments suggest that the CARD, coiledâcoil, SH3 and GUK domains of CARD11 are critical for its signaling function. These results implicate CARD11 in factorâ specific activation of NFâÎșB by the TCR complex and establish a role for a MAGUK family member in antigen receptor signaling
Optical Coherence Tomography Used as a Modality to Delineate Basal Cell Carcinoma prior to Mohs Micrographic Surgery
Optical coherence tomography (OCT) has potential as a modality for in vivo imaging of non-melanoma skin cancer (NMSC). By allowing identification of sub-surface margins of NMSC lesions, the use of OCT could improve the rate of complete excision and reduce the average number of stages during Mohs micrographic surgery (MMS). The objective of this study was to use OCT to delineate the apparent sub-surface margins of NMSC lesions prior to their excision by MMS. Lesions were scanned with reference to a physical marker on the skin, and the apparent margins were then identified from the OCT images and marked on the skin. Photographs of these margins and the Mohs defect were correlated and compared. OCT appears capable of visualizing the transition from lesional to normal tissue. In this case study, margins marked by use of the OCT system before surgery exhibit excellent correlation with the MMS defect. OCT offers the promise of better outcomes by enabling accurate margin mapping of NMSC in advance of MMS. Priorities now are to demonstrate this capability in a larger study, and to understand clearly indications and contraindications for use
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