60 research outputs found
Governance mandates, outside directors, and acquirer performance.
We use hand-collected board data around the issuance of two distinct government-led board structure mandates in the U.K. to establish the effect of outside directors on acquirer performance. Increases in outside director representation are associated with better acquirer returns in deals involving listed targets, but not when the target is private. These results are consistent with greater outside director reputational exposure when publicity is high. While we do not advocate mandated board structures, our evidence suggests that the particular diktats we examine were associated with improved acquirer performance in public firm takeovers. We present corroborating evidence from the U.S. around a similar reform period
Transgenerational Adaptation of Arabidopsis to Stress Requires DNA Methylation and the Function of Dicer-Like Proteins
Epigenetic states and certain environmental responses in mammals and seed plants can persist in the next sexual generation. These transgenerational effects have potential adaptative significance as well as medical and agronomic ramifications. Recent evidence suggests that some abiotic and biotic stress responses of plants are transgenerational. For example, viral infection of tobacco plants and exposure of Arabidopsis thaliana plants to UVC and flagellin can induce transgenerational increases in homologous recombination frequency (HRF). Here we show that exposure of Arabidopsis plants to stresses, including salt, UVC, cold, heat and flood, resulted in a higher HRF, increased global genome methylation, and higher tolerance to stress in the untreated progeny. This transgenerational effect did not, however, persist in successive generations. Treatment of the progeny of stressed plants with 5-azacytidine was shown to decrease global genomic methylation and enhance stress tolerance. Dicer-like (DCL) 2 and DCL3 encode Dicer activities important for small RNA-dependent gene silencing. Stress-induced HRF and DNA methylation were impaired in dcl2 and dcl3 deficiency mutants, while in dcl2 mutants, only stress-induced stress tolerance was impaired. Our results are consistent with the hypothesis that stress-induced transgenerational responses in Arabidopsis depend on altered DNA methylation and smRNA silencing pathways
Form and width of spectral line of Josephson Flux-Flow oscillator
The behavior of a Josephson flux-flow oscillator in the presence of both bias
current and magnetic field fluctuations has been studied. To derive the
equation for slow phase dynamics in the limit of small noise intensity the
Poincare method has been used. Both the form of spectral line and the linewidth
of the flux-flow oscillator have been derived exactly on the basis of technique
presented in the book of Malakhov, known limiting cases are considered, limits
of their applicability are discussed and appearance of excess noise is
explained. Good coincidence of theoretical description with experimental
results has been demonstrated.Comment: 10 pages, 5 figure
Spectrum of Andreev bound states in Josepshon junctions with a ferromagnetic insulator
Ferromagnetic-insulator (FI) based Josephson junctions are promising
candidates for a coherent superconducting quantum bit as well as a classical
superconducting logic circuit. Recently the appearance of an intriguing
atomic-scale 0-pi transition has been theoretically predicted. In order to
uncover the mechanism of this phenomena, we numerically calculate the spectrum
of Andreev bound states in a FI barrier by diagonalizing the Bogoliubov-de
Gennes equation. We show that Andreev spectrum drastically depends on the
parity of the FI-layer number L and accordingly the pi (0) state is always more
stable than the 0 (pi) state if L is odd (even).Comment: 6 pages, 5 figures, Invited Report on the Moscow International
Symposium on Magnetism MISM201
Revealing Josephson vortex dynamics in proximity junctions below critical current
Made of a thin non-superconducting metal (N) sandwiched by two
superconductors (S), SNS Josephson junctions enable novel quantum
functionalities by mixing up the intrinsic electronic properties of N with the
superconducting correlations induced from S by proximity. Electronic properties
of these devices are governed by Andreev quasiparticles [1] which are absent in
conventional SIS junctions whose insulating barrier (I) between the two S
electrodes owns no electronic states. Here we focus on the Josephson vortex
(JV) motion inside Nb-Cu-Nb proximity junctions subject to electric currents
and magnetic fields. The results of local (Magnetic Force Microscopy) and
global (transport) experiments provided simultaneously are compared with our
numerical model, revealing the existence of several distinct dynamic regimes of
the JV motion. One of them, identified as a fast hysteretic entry/escape below
the critical value of Josephson current, is analyzed and suggested for
low-dissipative logic and memory elements.Comment: 11 pages, 3 figures, 1 table, 43 reference
Genomic and Epigenomic Responses to Chronic Stress Involve miRNA-Mediated Programming
Stress represents a critical influence on motor system function and has been shown to impair movement performance. We hypothesized that stress-induced motor impairments are due to brain-specific changes in miRNA and protein-encoding gene expression. Here we show a causal link between stress-induced motor impairment and associated genetic and epigenetic responses in relevant central motor areas in a rat model. Exposure to two weeks of mild restraint stress altered the expression of 39 genes and nine miRNAs in the cerebellum. In line with persistent behavioural impairments, some changes in gene and miRNA expression were resistant to recovery from stress. Interestingly, stress up-regulated the expression of Adipoq and prolactin receptor mRNAs in the cerebellum. Stress also altered the expression of Prlr, miR-186, and miR-709 in hippocampus and prefrontal cortex. In addition, our findings demonstrate that miR-186 targets the gene Eps15. Furthermore, we found an age-dependent increase in EphrinB3 and GabaA4 receptors. These data show that even mild stress results in substantial genomic and epigenomic changes involving miRNA expression and associated gene targets in the motor system. These findings suggest a central role of miRNA-regulated gene expression in the stress response and in associated neurological function
The reputation of economic agents in mergers and acquisitions
EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Post-acquisition performance of private acquirers
We provide the first evidence on the performance of private operating firms as acquirers. Private bidders experience greater post-acquisition operating performance improvements compared to public bidders. This effect is not due to differences in target types, merger accounting, financing constraints, private equity ownership or subsequent listing of some private bidders, and is robust to instrumentation. Further analysis of governance arrangements at least partially attributes the private bidder effect to lower agency costs in private firms. Not only do private firms pay lower prices for target firm assets, they also operate them more efficiently by containing overhead costs and capital expenditures.•Private bidders experience greater operating performance changes around takeovers compared to public bidders.•This is not driven by differences in target types, merger accounting, financing constraints, or private equity ownership.•The effect is concentrated among private bidders whose governance arrangements suggest lower agency costs.•Private bidders pay lower transaction multiples and generate higher operating efficiencies through lower SG&A and CAPEX
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