Do CEOs and Principal Financial Officers Take a Bath Separately or Together?: An Investigation of Discretionary Accruals Surrounding Appointments of New CEOs and PFOs

This study presents the first targeted examination of changes in financial reporting surrounding the appointment of both new CEOs and Principal Financial Officers (PFOs). We identify companies that appoint new CEOs and PFOs in the period 1995 to 2002 and find that the change in discretionary accruals is negative and significant in the year of hire (from t-1 to t) for firms appointing a new CEO or both a new CEO and PFO (i.e., the big bath ), but not for firms appointing only a new PFO. We also find that firms appointing both executives in the same year report significant increases in discretionary accruals in the subsequent year (from t to t+1) and for the combined two-years surrounding the joint appointments (from t-1 to t+1). However, similar increases are not found for firms hiring only one of these executives. Additional analyses indicate that our results are robust when examining other discretionary financial reporting choices (i.e., special items, extraordinary items and discontinued operations), and that the type of compensation contract offered by the firm (i.e., having a high bonus component ) is not significantly related to the changes in discretionary accruals surrounding these appointments. Our findings contribute to the corporate governance and executive turnover literature and provide evidence of a heightened financial reporting effect when firms concurrently appoint both new CEOs and PFOs

Transport in Floquet-Bloch bands

We report Floquet band engineering of long-range transport and direct imaging of Floquet-Bloch bands in an amplitude-modulated optical lattice. In one variety of Floquet-Bloch band we observe tunable rapid long-range high-fidelity transport of a Bose condensate across thousands of lattice sites. Quenching into an opposite-parity Floquet-hybridized band allows Wannier-Stark localization to be controllably turned on and off using modulation. A central result of this work is the use of transport dynamics to demonstrate direct imaging of a Floquet-Bloch band structure. These results demonstrate that transport in dynamical Floquet-Bloch bands can be mapped to transport in quasi-static effective bands, opening a path to cold atom quantum emulation of ultrafast multi-band electronic dynamics.Comment: 5 pages, 4 figure

Releasing Information in XBRL: Does It Improve Information Asymmetry for Early U.S. Adopters?

Information released in XBRL is intended to improve the quality and accessibility of SEC filings, leading to less information asymmetry in the equity market. Research findings on the effects of XBRL on information asymmetry in the US., however, are mixed. Kim et al. (2012) reports that XBRL reduces information asymmetry while Blankespoor et al. (2012) reports that XBRL increases information asymmetry. In contrast to these prior studies, we report that the answer as to whether XBRL affects information asymmetry is matter of firm size. In this study we examine shifts in two measures of information asymmetry for early adopters of XBRL in the US. Specifically, we find that the bid-ask spreads of early XBRL adopters significantly decrease after they adopt XBRL; yet, we find no overall change in trading volume associated with XBRL filings for early adopters. However, when examining the larger early adopting firms, we find evidence of reduced information asymmetry (bid-ask spreads significantly decrease and trading volume significantly increase). Our results generally support the SEC requirement of XBRL formatted financial information on the grounds that it may reduce information asymmetry of large filers in the US. equity market

Heavy resonance production in high energy nuclear collisions

We estimate freezeout conditions for $s$, $c$, and $b$ quarks in high energy nuclear collisions. Freezeout is due either to loss of thermal contact, or to particles ``wandering'' out of the region of hot matter. We then develop a thermal recombination model in which both single-particle (quark and antiquark) and two-particle (quark-antiquark) densities are conserved. Conservation of two-particle densities is necessary because quarks and antiquarks are always produced in coincidence, so that the local two-particle density can be much larger than the product of the single-particle densities. We use the freezeout conditions and recombination model to discuss heavy resonance production at zero baryon density in high energy nuclear collisions.Comment: revtex, 15 pages, no figures, KSUCNR-009-9

Experimental Realization of a Relativistic Harmonic Oscillator

We report the experimental study of a harmonic oscillator in the relativistic regime. The oscillator is composed of Bose-condensed lithium atoms in the third band of an optical lattice, which have an energy-momentum relation nearly identical to that of a massive relativistic particle, with an effective mass reduced below the bare value and a greatly reduced effective speed of light. Imaging the shape of oscillator trajectories at velocities up to 98% of the effective speed of light reveals a crossover from sinusoidal to nearly photon-like propagation. The existence of a maximum velocity causes the measured period of oscillations to increase with energy; our measurements reveal beyond-leading-order contributions to this relativistic anharmonicity. We observe an intrinsic relativistic dephasing of oscillator ensembles, and a monopole oscillation with exactly the opposite phase of that predicted for non-relativistic harmonic motion. All observed dynamics are in quantitative agreement with longstanding but hitherto-untested relativistic predictions.Comment: 10 pages; 4 figure

U.S. Naval Observatory VLBI Analysis Center

This report summarizes the activities of the VLBI Analysis Center at the United States Naval Observatory for the 2012 calendar year. Over the course of the year, Analysis Center personnel continued analysis and timely submission of IVS-R4 databases for distribution to the IVS. During the 2012 calendar year, the USNO VLBI Analysis Center produced two VLBI global solutions designated as usn2012a and usn2012b. Earth orientation parameters (EOP) based on this solution and updated by the latest diurnal (IVS-R1 and IVS-R4) experiments were routinely submitted to the IVS. Sinex files based upon the bi-weekly 24-hour experiments were also submitted to the IVS. During the 2012 calendar year, Analysis Center personnel continued a program to use the Very Long Baseline Array (VLBA) operated by the NRAO for the purpose of measuring UT1-UTC. Routine daily 1-hour duration Intensive observations were initiated using the VLBA antennas at Pie Town, NM and Mauna Kea, HI. High-speed network connections to these two antennas are now routinely used for electronic transfer of VLBI data over the Internet to a USNO point of presence. A total of 270 VLBA Intensive experiments were observed and electronically transferred to and processed at USNO in 2012

Biological and cultural history of domesticated dogs in the Americas

FIG. 1. — "Canis mexicana", a domestic dog with peculiar humps and apparent muscle hypertrophy, as depicted in 1651 by Hernández in his Rerum medicarum Novae Hispaniae thesaurus (Hernández 1992). Previously dismissed as a caricature (Ueck 1961), it may actually illustrate a phenotype associated with mutations in the myostatin gene. Picture retrieved from Internet Archive https://archive.org/details/rerummedicarumno00hern/page/466/mode/1up, last consultation on 30 November 2021.Published as part of Segura, Valentina, Geiger, Madeleine, Monson, Tesla A., Flores, David & Sánchez-Villagra, Marcelo R., 2022, Biological and cultural history of domesticated dogs in the Americas, pp. 1-18 in Anthropozoologica 57 (1) on page 4, DOI: 10.5252/anthropozoologica2022v57a1, http://zenodo.org/record/589748

Observation and uses of position-space Bloch oscillations in an ultracold gas

We report the direct observation and characterization of position-space Bloch oscillations using an ultracold gas in a tilted optical lattice. While Bloch oscillations in momentum space are a common feature of optical lattice experiments, the real-space center-of-mass dynamics are typically too small to resolve. Tuning into the regime of rapid tunneling and weak force, we observe real-space Bloch oscillation amplitudes of hundreds of lattice sites, in both ground and excited bands. We demonstrate two unique capabilities enabled by tracking of Bloch dynamics in position space: measurement of the full position-momentum phase-space evolution during a Bloch cycle, and direct imaging of the lattice band structure. These techniques, along with the ability to exert long-distance coherent control of quantum gases without modulation, may open up new possibilities for quantum control and metrology.Comment: 5 pages, 6 figure

Purines and Neuronal Excitability: Links to the Ketogenic Diet [post-print]

ATP and adenosine are purines that play dual roles in cell metabolism and neuronal signaling. Acting at the A(1) receptor (A(1)R) subtype, adenosine acts directly on neurons to inhibit excitability and is a powerful endogenous neuroprotective and anticonvulsant molecule. Previous research showed an increase in ATP and other cell energy parameters when an animal is administered a ketogenic diet, an established metabolic therapy to reduce epileptic seizures, but the relationship among purines, neuronal excitability and the ketogenic diet was unclear. Recent work in vivo and in vitro tested the specific hypothesis that adenosine acting at A(1)Rs is a key mechanism underlying the success of ketogenic diet therapy and yielded direct evidence linking A(1)Rs to the antiepileptic effects of a ketogenic diet. Specifically, an in vitro mimic of a ketogenic diet revealed an A(1)R-dependent metabolic autocrine hyperpolarization of hippocampal neurons. In parallel, applying the ketogenic diet in vivo to transgenic mouse models with spontaneous electrographic seizures revealed that intact A(1)Rs are necessary for the seizure-suppressing effects of the diet. This is the first direct in vivo evidence linking A(1)Rs to the antiepileptic effects of a ketogenic diet. Other predictions of the relationship between purines and the ketogenic diet are discussed. Taken together, recent research on the role of purines may offer new opportunities for metabolic therapy and insight into its underlying mechanisms