1,472 research outputs found
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
ON THE LOGIC OF GENERALIZED HYPERTEXT
Hypertext is one of those neat ideas in computing that periodically
burst upon the scene, quickly demonstrating their usefulness
and gaining widespread acceptance. As interesting, useful and exciting
as hypertext is, the concept has certain problems and limitations,
many of which are widely recognized. In this paper we describe what
we call basic hypertext and we present a logic model for it. Basic hypertext
should be thought of as a rigorously-presented approximation
of first-generation hypertext concepts. Following our discussion of basic
hypertext, we present our concept of generalized hypertext, which
is aimed at overcoming certain of the limitations of basic hypertext
and which we have implemented in a DSS shell called Max. We then
present a logic model for browsing in generalized hypertext.Information Systems Working Papers Serie
On the Logic of Generalized Hypertext
Hypertext is one of those neat ideas in computing that periodically burst upon the scene, quickly demonstrating their usefulness and gaining widespread acceptance. As interesting, useful and exciting as hypertext is, the concept has certain problems and limitations, many of which are widely recognized. In this paper we describe what we call basic hypertext and we present a logic model for it. Basic hypertext should be thought of as a rigorously-presented approximation of first-generation hypertext concepts. Following our discussion of basic hypertext, we present our concept of generalized hypertext, which is aimed at overcoming certain of the limitations of basic hypertext and which we have implemented in a DSS shell called Max. We then present a logic model for browsing in generalized hypertext
Measurement of the electric fluctuation spectrum of magnetohydrodynamic turbulence
Magnetohydrodynamic (MHD) turbulence in the solar wind is observed to show
the spectral behavior of classical Kolmogorov fluid turbulence over an inertial
subrange and departures from this at short wavelengths, where energy should be
dissipated. Here we present the first measurements of the electric field
fluctuation spectrum over the inertial and dissipative wavenumber ranges in a
plasma. The inertial subrange is observed and
agrees strikingly with the magnetic fluctuation spectrum; the wave phase speed
in this regime is shown to be consistent with the Alfv\'en speed. At smaller
wavelengths the electric spectrum is softer and is consistent
with the expected dispersion relation of short-wavelength kinetic Alfv\'en
waves. Kinetic Alfv\'en waves damp on the solar wind ions and electrons and may
act to isotropize them. This effect may explain the fluid-like nature of the
solar wind.Comment: submitted; 4 pages + 3 figure
HLA-G: expression in human keratinocytes in vitro and in human skin in vivo
Classical, polymorphic major histocompatibility complex class I molecules are
expressed on most nucleated cells.They present peptides at the cell surface and,
thus, enable the immune system to scan peptides for their antigenicity. The
function of the other, nonclassical class I molecules in man is controversial.
HLA-G which has been shown by transfection experiments to be expressed at the
cell surface, is only transcribed in placental tissue and in the fetal eye.Therefore, a
role of HLA-G in the control of rejection of the allogeneic fetus has been
discussed. We found that HLA-G expression is induced in keratinocytes by
culture in vitro. Three different alternative splicing products of HLA-G can be
detected: a full length transcript, an mRNA lacking exon 3 and a transcript devoid
of exon 3 and 4. Reverse transcription followed by polymerase chain reaction also
revealed the presence of HLA-G mRNA in vivo in biopsies of either diseased or
healthy skin
Research on oxygen toxicity at the cellular level Final report, 15 Apr. 1965 - 15 Jun. 1966
Oxygen toxicity at cellular level in manned spacecraf
River Otter Distribution in Nebraska
The river otter (Lontra canadensis) was extirpated from Nebraska, USA, in the early 1900s and reintroduced starting in 1986. Information is needed regarding the distribution of river otters in Nebraska before decisions can be made regarding its conservation status. Understanding distribution of a species is critically important for effective management. We investigated river otter distribution in Nebraska with occupancy modeling and maximum entropy (Maxent) modeling using 190 otter sign observations on Nebraska’s navigable rivers and 380 historical otter records from November 1977 to April 2014. Both methods identified the Platte River, Elkhorn River, central and eastern Niobrara River, and southern Loup River system as core areas within the distribution of otters in Nebraska. The Maxent model provided more liberal estimates of site occupancy and identified some smaller rivers as being within the distribution of otters in Nebraska, which were not identified using occupancy modeling. We recommend that multiple data sets and analysis methods be used to estimate species distribution because this allows for the broadest geographical coverage and decreases the likelihood of overlooking areas with fewer animal records. If further reintroduction efforts or translocation efforts are to take place in the future, we recommend focusing on areas with high modeled occupancy but few historical and survey records
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