17,398 research outputs found
Dimensional Effects on the Density of States in Systems with Quasi-Relativistic Dispersion Relations and Potential Wells
Motivated by the recent discoveries of materials with quasi-relativistic
dispersion relations, we determine densities of states in materials with low
dimensional substructures and relativistic dispersion relations. We find that
these dimensionally hybrid systems yield quasi-relativistic densities of states
that are a superposition of the corresponding two- and three-dimensional
densities of states.Comment: To be submitted to the Canadian Journal of Physics, 8 pages, 4 figue
Gravity and the Newtonian limit in the Randall-Sundrum model
We point out that the gravitational evolution equations in the
Randall-Sundrum model appear in a different form than hitherto assumed. As a
consequence, the model yields a correct Newtonian limit in a novel manner.Comment: 9 pages, LaTeX, sign changed and references added. We have also
appended a remark on the compatibility of the 4D Poincare invariant metric of
Randall and Sundrum with the boundary equation
Expertise with non-speech 'auditory Greebles' recruits speech-sensitive cortical regions
Regions of the human temporal lobe show greater activation for speech than for other sounds. These differences may reflect intrinsically specialized domain-specific adaptations for processing speech, or they may be driven by the significant expertise we have in listening to the speech signal. To test the expertise hypothesis, we used a video-game-based paradigm that tacitly trained listeners to categorize acoustically complex, artificial nonlinguistic sounds. Before and after training, we used functional MRI to
measure how expertise with these sounds modulated temporal lobe activation. Participants’ ability to explicitly categorize the nonspeech sounds predicted the change in pretraining to posttraining activation in speech-sensitive regions of the left posterior superior temporal sulcus, suggesting that emergent auditory expertise may help drive this functional regionalization. Thus, seemingly domain-specific patterns of neural activation in higher cortical regions may be driven in part by experience-based
restructuring of high-dimensional perceptual space
Multiple uses of water in irrigated areas: a case study from Sri Lanka
Water management / Water allocation / Water use efficiency / Irrigated farming / Water resources development / Water policy / Water quality / Domestic water / Water users' associations / Water rights / Gender / Households / Pricing / Water costs / Case studies / Sri Lanka / Kirindi Oya
Effects of pH on Growth of Salvinia molesta Mitchell
Growth of giant salvinia (
Salvinia molesta
Mitchell) under
different pH regimes was examined at the Lewisville Aquatic
Ecosystem Research Facility (LAERF) in Lewisville, Texas.(PDF has 5 pages.
Energy Dependent Contrast in Atomic-Scale Spin-Polarized Scanning Tunneling Microscopy ofMn3N2(010): Experiment and First-Principles Theory
The technique of spin-polarized scanning tunneling microscopy is investigated
for its use in determining fine details of surface magnetic structure down to
the atomic scale. As a model sample, the row-wise anti-ferromagnetic Mn3N2(010)
surface is studied. It is shown that the magnetic contrast in atomic-scale
images is a strong function of the bias voltage around the Fermi level.
Inversion of the magnetic contrast is also demonstrated. The experimental
SP-STM images and height profiles are compared with simulated SP-STM images and
height profiles based on spin-polarized density functional theory. The success
of different tip models in reproducing the non-magnetic and magnetic STM data
is explored.Comment: 15 pages, 7 figure
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