5,458 research outputs found
Spectral asymptotics of a broken delta interaction
This paper is concerned with the spectral analysis of a Hamiltonian with a
-interaction supported along a broken line with angle . The
bound states with energy slightly below the threshold of the essential spectrum
are estimated in the semiclassical regime .Comment: 20 page
Spectral asymptotics for the Schr\"odinger operator on the line with spreading and oscillating potentials
This study is devoted to the asymptotic spectral analysis of multiscale
Schr\"odinger operators with oscillating and decaying electric potentials.
Different regimes, related to scaling considerations, are distinguished. By
means of a normal form filtrating the oscillations, a reduction to a
non-oscillating effective Hamiltonian is performed
Characterization of a Dominant Negative Mutant of the Cell Cycle Ubiquitin-conjugating Enzyme Cdc34
The yeast Saccharomyces cerevisiae CDC34 gene encodes a ubiquitin-conjugating enzyme that is required for the cell cycle G(1)/S transition. We show here that a dominant negative Cdc34 protein is generated by simultaneously replacing both Cys and Leu with Ser residues. Cys is an essential catalytic residue that forms a transient thiol ester with ubiquitin during catalysis, and Leu is highly conserved among all known ubiquitin-conjugating enzymes. Mutants that encode either an alanine or a serine at one or both of these two positions are inactive. Of these eight mutants, overexpression of CDC34-C95S,L99S in wild type strains was found to block cell growth. Although cells overexpressing Cdc34-C95S,L99S do not exhibit the characteristic multibudded phenotype of cdc34 temperature-sensitive or null mutants, this blockade is relieved by simultaneous overexpression of wild type Cdc34. Purified Cdc34-C95S,L99S protein can be shown to inhibit in vitro ubiquitination of the Cdc34-specific substrate, Cln2 protein. We suggest that Cdc34-C95S,L99S selectively sequesters a subset of Cdc34 substrates or regulators. These findings have implications for the structure/function relationships of ubiquitin-conjugating enzymes, and suggest a general method for identifying components and substrates of specific ubiquitination pathways of eukaryotes
Anisotropic susceptibility of the geometrically frustrated spin-chain compound Ca3Co2O6
Ca3Co2O6 is a system exhibiting a series of fascinating properties, including
magnetization plateaus and remarkably slow dynamics at low-T. These properties
are intimately related to the geometrical frustration, which results from a
particular combination of features: (i) the chains are arranged on a triangular
lattice; (ii) there is a large uniaxial anisotropy; (iii) the intrachain and
interchain couplings are ferromagnetic and antiferromagnetic, respectively.
The uniaxial anisotropy is thus an issue of crucial importance for the
analysis of the physical properties of Ca3Co2O6. However, it turns out that no
precise investigation of this magnetic anisotropy has been performed so far. On
the basis of susceptibility data directly recorded on single crystals, the
present study reports on quantitative information about the anisotropy of
Ca3Co2O6.Comment: 10 pages, 5 figure
Human middle temporal cortex, perceptual bias, and perceptual memory for ambiguous three-dimensional motion
When faced with inconclusive or conflicting visual input human observers experience one of multiple possible perceptions. One factor that determines perception of such an ambiguous stimulus is how the same stimulus was perceived on previous occasions, a phenomenon called perceptual memory. We examined perceptual memory of an ambiguous motion stimulus while applying transcranial magnetic stimulation (TMS) to the motion-sensitive areas of the middle temporal cortex (hMT+). TMS increased the predominance of whichever perceptual interpretation was most commonly reported by a given observer at baseline, with reduced perception of the less favored interpretation. This increased incidence of the preferred percept indicates impaired long-term buildup of perceptual memory traces that normally act against individual percept biases. We observed no effect on short-term memory traces acting from one presentation to the next. Our results indicate that hMT+ is important for the long-term buildup of perceptual memory for ambiguous motion stimuli
Scenic Design for Anton Chekhov\u27s Three Sisters
This thesis document is a written account of my scenic design process. The initial discussions with the director led to the finished set onstage for a production of Three Sisters by Anton Chekhov. The Play was produced by West Virginia University\u27s School of Theatre & Dance, presented in the Gladys G. Davis Theater at the Creative Arts Center in Morgantown, WV. The production dates ran from November 16th-30th and December 1st - 2nd, 2017. This document comprises the scenic design appointment through my analysis of the script, the design process, the execution of the design, and finally my analysis of the assignment
A Geometric Model for Odd Differential K-theory
Odd -theory has the interesting property that it admits an infinite number
of inequivalent differential refinements. In this paper we provide a bundle
theoretic model for odd differential -theory using the caloron
correspondence and prove that this refinement is unique up to a unique natural
isomorphism. We characterise the odd Chern character and its transgression form
in terms of a connection and Higgs field and discuss some applications. Our
model can be seen as the odd counterpart to the Simons-Sullivan construction of
even differential -theory. We use this model to prove a conjecture of
Tradler-Wilson-Zeinalian regarding a related differential extension of odd
-theoryComment: 36 page
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