The elimination of broker voting in director elections

In 2009, the Securities and Exchange Commission (SEC) reformed shareholder voting by eliminating uninstructed broker voting in director elections. We use this reform as a quasi-natural experiment to assess the value of shareholder empowerment. Using different control groups and various cross-sectional tests, we find that the reform did not increase average equity values

Counting Statistics of Many-Particle Quantum Walks

We study quantum walks of many non-interacting particles on a beam splitter array, as a paradigmatic testing ground for the competition of single- and many-particle interference in a multi-mode system. We derive a general expression for multi-mode particle-number correlation functions, valid for bosons and fermions, and infer pronounced signatures of many-particle interferences in the counting statistics.Comment: 4 pages, 4 figure

The Effect of Participating in a Fitness and Lifetime Skills Program on Attitude Toward Physical Activity

The purpose of this investigation was to determine if student attitude toward physical activity changed following exposure to one semester of fitness and lifetime skills instruction. The study specifically examined attitude difference and change by gender and class level for 343 college aged males and females. Subjects for the study were selected via a stratified random sample of courses offered within the Physical Education 100 Fitness and Lifetime Skills Program. Attitude measurements were obtained utilizing Kenyon\u27s multi-dimensional Attitude Toward Physical Activity and Body Image Inventory administered in a test-retest procedure. A two-way analysis of variance (ANOVA) revealed significant pretest differences for gender and class level (p \u3c .05). Males and females differed significantly on the variables (a) pursuit of vertigo, (b) aesthetic experience, (c) catharsis, and (d) ideal body image. Freshmen/sophomores held significantly different attitudes toward physical activity (ATPA) than juniors/seniors for the dimensions of (a) social experience, (b) pursuit of vertigo, (c) catharsis, and (d) overall ATPA. Repeated measures ANOVA\u27s were performed to determine if attitudes changed significantly from pretest to posttest. Findings indicated a significant increase in ATPA as a social experience, health and fitness, aesthetic experience, and catharsis. Also, significant class level interactions were observed on the ascetic, catharsis, and perceived body image dimensions. It was concluded that attitudes toward certain dimensions of physical activity can change following participation in one semester of fitness and lifetime skills instruction

Real-time observation of epitaxial graphene domain reorientation.

Graphene films grown by vapour deposition tend to be polycrystalline due to the nucleation and growth of islands with different in-plane orientations. Here, using low-energy electron microscopy, we find that micron-sized graphene islands on Ir(111) rotate to a preferred orientation during thermal annealing. We observe three alignment mechanisms: the simultaneous growth of aligned domains and dissolution of rotated domains, that is, 'ripening'; domain boundary motion within islands; and continuous lattice rotation of entire domains. By measuring the relative growth velocity of domains during ripening, we estimate that the driving force for alignment is on the order of 0.1 meV per C atom and increases with rotation angle. A simple model of the orientation-dependent energy associated with the moiré corrugation of the graphene sheet due to local variations in the graphene-substrate interaction reproduces the results. This work suggests new strategies for improving the van der Waals epitaxy of 2D materials

The Maximum Optical Depth Towards Bulge Stars From Axisymmetric Models of the Milky Way

It has been known that recent microlensing results towards the bulge imply mass densities that are surprisingly high given dynamical constraints on the Milky Way mass distribution. We derive the maximum optical depth towards the bulge that may be generated by axisymmetric structures in the Milky Way, and show that observations are close to surpassing these limits. This result argues in favor of a bar as a source of significantly enhanced microlensing. Several of the bar models in the literature are discussed.Comment: Latex, 6 pages, 4 figures, uses aas2pp4 and epsf style files. Accepted for publication in ApJ Letter

Conduction Channels of One-Atom Zinc Contacts

We have determined the transmission coefficients of atomic-sized Zn contacts using a new type of breakjunction which contains a whisker as a central bridge. We find that in the last conductance plateau the transport is unexpectedly dominated by a well-transmitting single conduction channel. We explain the experimental findings with the help of a tight-binding model which shows that in an one-atom Zn contact the current proceeds through the 4s and 4p orbitals of the central atom.Comment: revtex4, 5 pages, 5 figure

A Comparison of Quantum Oracles

A standard quantum oracle $S_f$ for a general function $f: Z_N \to Z_N$ is defined to act on two input states and return two outputs, with inputs $\ket{i}$ and $\ket{j}$ ($i,j \in Z_N$) returning outputs $\ket{i}$ and $\ket{j \oplus f(i)}$. However, if $f$ is known to be a one-to-one function, a simpler oracle, $M_f$, which returns $\ket{f(i)}$ given $\ket{i}$, can also be defined. We consider the relative strengths of these oracles. We define a simple promise problem which minimal quantum oracles can solve exponentially faster than classical oracles, via an algorithm which cannot be naively adapted to standard quantum oracles. We show that $S_f$ can be constructed by invoking $M_f$ and $(M_f)^{-1}$ once each, while $\Theta(\sqrt{N})$ invocations of $S_f$ and/or $(S_f)^{-1}$ are required to construct $M_f$.Comment: 4 pages, 1 figure; Final version, with an extended discussion of oracle inverses. To appear in Phys Rev

Heralded single-photon generation using imperfect single-photon sources and a two-photon-absorbing medium

We propose a setup for a heralded, i.e. announced generation of a pure single-photon state given two imperfect sources whose outputs are represented by mixtures of the single-photon Fock state $\ket{1}$ with the vacuum $\ket{0}$. Our purification scheme uses beam splitters, photodetection and a two-photon-absorbing medium. The admixture of the vacuum is fully eliminated. We discuss two potential realizations of the scheme.Comment: 22 pages, 8 figures (LaTeX). In version v2 we have slightly modified our setup so as to increase the success probability of single-photon generation by a factor of two. In addition, in an appendix we discuss alternative realizations of single-photon generation without a Mach-Zehnder interferometer. Three new figures have been added. Version v3 is a revised version published in Phys. Rev. A. It contains numerous minor corrections and clarifications. A new figure has been added in order to clarify our convention regarding labelling the field modes. The action of the beam splitters in the Schroedinger picture is introduced. A new reference has been include