13,044 research outputs found
Study of shell supported ring frames with out- of-plane loading Final report, 24 Jun. - 28 Dec. 1965
Deflections and internal loading distribution of circular cylindrical shell supported ring frames with out-of-plane loading
Evidence against the Detectability of a Hippocampal Place Code Using Functional Magnetic Resonance Imaging
Individual hippocampal neurons selectively increase their firing rates in specific spatial locations. As a population, these neurons provide a decodable representation of space that is robust against changes to sensory- and path-related cues. This neural code is sparse and distributed, theoretically rendering it undetectable with population recording methods such as functional magnetic resonance imaging (fMRI). Existing studies nonetheless report decoding spatial codes in the human hippocampus using such techniques. Here we present results from a virtual navigation experiment in humans in which we eliminated visual- and path-related confounds and statistical limitations present in existing studies, ensuring that any positive decoding results would represent a voxel-place code. Consistent with theoretical arguments derived from electrophysiological data and contrary to existing fMRI studies, our results show that although participants were fully oriented during the navigation task, there was no statistical evidence for a place code
On the predictive power of Local Scale Invariance
Local Scale Invariance (LSI) is a theory for anisotropic critical phenomena
designed in the spirit of conformal invariance. For a given representation of
its generators it makes non-trivial predictions about the form of universal
scaling functions. In the past decade several representations have been
identified and the corresponding predictions were confirmed for various
anisotropic critical systems. Such tests are usually based on a comparison of
two-point quantities such as autocorrelation and response functions. The
present work highlights a potential problem of the theory in the sense that it
may predict any type of two-point function. More specifically, it is argued
that for a given two-point correlator it is possible to construct a
representation of the generators which exactly reproduces this particular
correlator. This observation calls for a critical examination of the predictive
content of the theory.Comment: 17 pages, 2 eps figure
Peppering the Bostonian Palate : Two Silver Casters by Paul Revere II
"Composed in 1860 by Henry Wadsworth Longfellow and published in his Tales of a Wayside Inn (1863), these oft-quoted lines resurrected from obscurity the name of Paul Revere, whose patriotic ride in Revolutionary America is remembered by many rather than his fame as a silversmith. The descendants of those Bostonian families fortunate enough to have been able to commission plate from Paul Revere have not forgotten the name stamped on their silver. Even if Revere had not taken that "midnight ride," his mastery in the working of silver would be treasured by collectors and museums alike."--First paragraph.Includes bibliographical reference
A Flower-Piece and Napoleon
"Among the most appreciated Dutch genre paintings are flower-pieces. In 1964 the Museum of Art and Archaeology became the recipient of a flower-piece signed by the illustrious early eighteenth-century flower-painter Jan van Huysum."--First paragraph.Includes bibliographical reference
Effects of cocaethylene on dopamine and serotonin synthesis in Long–Evans and Sprague–Dawley brains
We examined the behavioral and neurochemical effects of cocaethylene treatment in Long–Evans (�LE). and Sprague–Dawley� (SD) rats. Cocaethylene-induced behaviors were significantly less in LE rats. Cocaethylene caused an inhibition of dopamine synthesis in the caudate nucleus and nucleus accumbens that was equivalent in both rat lines. Serotonin synthesis was also suppressed by cocaethylene treatment, however this phenomenon was less pronounced when compared with the effects on dopamine synthesis
Desensitizing Inflation from the Planck Scale
A new mechanism to control Planck-scale corrections to the inflationary eta
parameter is proposed. A common approach to the eta problem is to impose a
shift symmetry on the inflaton field. However, this symmetry has to remain
unbroken by Planck-scale effects, which is a rather strong requirement on
possible ultraviolet completions of the theory. In this paper, we show that the
breaking of the shift symmetry by Planck-scale corrections can be
systematically suppressed if the inflaton field interacts with a conformal
sector. The inflaton then receives an anomalous dimension in the conformal
field theory, which leads to sequestering of all dangerous high-energy
corrections. We analyze a number of models where the mechanism can be seen in
action. In our most detailed example we compute the exact anomalous dimensions
via a-maximization and show that the eta problem can be solved using only
weakly-coupled physics.Comment: 34 pages, 3 figures
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