Board interlocks and earnings management contagion

We examine whether earnings management spreads from firm to firm via board connections of shared directors. A firm has a higher likelihood of restating earnings in a given year if it shares a director with another firm that restated earnings either in that same year or within the past two years. We also find evidence of earning management contagion at the earlier restating period when the accounting violated GAAP. In this case, a firm has a higher probability of later restating earnings reported in the current year if it shares a director with other firms that have to restate earnings for the current or past two years. Furthermore, we find that earnings management contagion is stronger when it’s the shared director has a more important relevant position. A board chairman, audit committee member or especially audit committee chairman who is also a director at another firm is associated with stronger contagion relative to other board positions of shared directors. This finding is consistent with the importance of the role of board monitoring to ensure high quality financial reporting. Board network contagion effects are not due to reverse causality, endogenous matching of firm characteristics or common industry shocks, but are weakened by endogenous matching of director characteristics. Board network contagion effects also subsume contagion from geographical proximity of firms, and are incremental to other sources of earnings management incentives, such as M&A and new issue activities. Overall, the evidence supports the idea that economic behaviors such as earnings manipulation spread through social networks.postprin

Flux qubit on mesoscopic nonsuperconducting ring

The possibility of making a flux qubit on nonsuperconducting mesoscopic ballistic quasi 1D ring is discussed. We showed that such ring can be effectively reduced to a two-state system with two external control parameters. The two states carry opposite persistent currents and are coupled by tunneling which leads to a quantum superposition of states. The qubit states can be manipulated by resonant microwave pulses. The flux state of the sample can be measured by a SQUID magnetometer. Two or more qubits can be coupled by the flux the circulating currents generate. The problem of decoherence is also discussed.Comment: Phys. Rev. B. (accepted

Local chromatin dynamics of transcription factors imply cell-lineage specific functions during cellular differentiation

Chromatin dynamics across cellular differentiation states is an emerging perspective from which the mechanism of global gene expression regulation may be better understood. While the roles of some histone marks have been partially interpreted in terms of their association with gene transcription, the dynamics of histone marks from a loci-specific perspective during cellular differentiation is not well studied. We established a method to systematically assess the histone modification variations of genes across various cellular differentiation states. We calculated the histone modification variation scores of H3K4me3, H3K27me3 and H3K36me3 for over 1300 curated transcription factors (TFs) during human blood cell differentiation. Hematopoietic-specific TFs (identified by literature mining) were significantly overrepresented by TFs with higher histone modification variation scores. Hierarchical clustering of all TFs based on the histone modification variation scores defined a group of TFs where known or potential hematopoietic-specific TFs were remarkably enriched. Our results suggest that local chromatin state dynamics of transcription factors across cellular differentiation states could imply cell lineage-specific functions. More importantly, our method can be applied to broader systems, holding the promise to discover de novo, lineage-specific TFs by interrogating their histone modification dynamics across cell lineages

An artifacts removal post-processing for epiphyseal region-of-interest (EROI) localization in automated bone age assessment (BAA)

<p>Abstract</p> <p>Background</p> <p>Segmentation is the most crucial part in the computer-aided bone age assessment. A well-known type of segmentation performed in the system is adaptive segmentation. While providing better result than global thresholding method, the adaptive segmentation produces a lot of unwanted noise that could affect the latter process of epiphysis extraction.</p> <p>Methods</p> <p>A proposed method with anisotropic diffusion as pre-processing and a novel Bounded Area Elimination (BAE) post-processing algorithm to improve the algorithm of ossification site localization technique are designed with the intent of improving the adaptive segmentation result and the region-of interest (ROI) localization accuracy.</p> <p>Results</p> <p>The results are then evaluated by quantitative analysis and qualitative analysis using texture feature evaluation. The result indicates that the image homogeneity after anisotropic diffusion has improved averagely on each age group for 17.59%. Results of experiments showed that the smoothness has been improved averagely 35% after BAE algorithm and the improvement of ROI localization has improved for averagely 8.19%. The MSSIM has improved averagely 10.49% after performing the BAE algorithm on the adaptive segmented hand radiograph.</p> <p>Conclusions</p> <p>The result indicated that hand radiographs which have undergone anisotropic diffusion have greatly reduced the noise in the segmented image and the result as well indicated that the BAE algorithm proposed is capable of removing the artifacts generated in adaptive segmentation.</p

Development of highly efficient, renewable and durable alginate composite aerogels for oil/water separation

Supplementary Movie S1 is available online at https://www.sciencedirect.com/science/article/pii/S0257897220302206?via%3Dihub#ac0005:~:text=Download%20all-,Supplementary%20Movie%20S1,-Supplemtantary%20information%20for .Supplementary information is available online at https://www.sciencedirect.com/science/article/pii/S0257897220302206?via%3Dihub#ec0010 .To valorize the naturally abundant biomass, bio-composites made of biomass and functional nano-materials have attracted a great deal of attention. By incorporating alginate with TiO2/RGO nanocomposites, TiO2/RGO/Alginate composite (TRGA) aerogels are fabricated via a facile freeze-drying method. TiO2/RGO nanocomposites can effectively improve the surface roughness and mechanical performance of alginate-based matrix, and provide the aerogels with light-driven self-cleaning ability. Without further chemical modification, the as-fabricated TRGA aerogel shows: i) collective underwater superoleophobicity (θoil > 150° for various oils), ii) effective oil/water separation performance (9.76 L·m−2·s−1 water permeate flux and 99.96% separation efficiency) and iii) excellent light-induced recyclability. With light-driven self-cleaning ability, the continuously deteriorated separation performance of aerogel can be easily renewed, and maintain an effective oil/water separation performance even after 120 cycles. Benefiting from its facile fabrication and excellent properties, the developed aerogel can be a promising candidate for practical oil/water separation in marine oil spill clean-up applications.This work is financially supported by the Program for New Century Excellent Talents in Fujian Province University (NCETFJ); Natural Science Foundation of Fujian Province (No. 2016J01207); Youth Education and Scientific of Fujian Province (No. JAT170154); and Outstanding Youth Fund of Fujian Agriculture and Forestry University (No. XJQ201419, CXZX2017292)

EGFR Gene Overexpression Retained in an Invasive Xenograft Model by Solid Orthotopic Transplantation of Human Glioblastoma Multiforme Into Nude Mice

Orthotopic xenograft animal model from human glioblastoma multiforme (GBM) cell lines often do not recapitulate an extremely important aspect of invasive growth and epidermal growth factor receptor (EGFR) gene overexpression of human GBM. We developed an orthotopic xenograft model by solid transplantation of human GBM into the brain of nude mouse. The orthotopic xenografts sharing the same histopathological features with their original human GBMs were highly invasive and retained the overexpression of EGFR gene. The murine orthotopic GBM models constitute a valuable in vivo system for preclinical studies to test novel therapies for human GBM

Gold nanocrystals with variable index facets as highly effective cathode catalysts for lithium-oxygen batteries

© 2015 Nature Publishing Group All rights reserved. Cathode catalysts are the key factor in improving the electrochemical performance of lithium-oxygen (Li-O2) batteries via their promotion of the oxygen reduction and oxygen evolution reactions (ORR and OER). Generally, the catalytic performance of nanocrystals (NCs) toward ORR and OER depends on both composition and shape. Herein, we report the synthesis of polyhedral Au NCs enclosed by a variety of index facets: cubic gold (Au) NCs enclosed by {100} facets; truncated octahedral Au NCs enclosed by {100} and {110} facets; and trisoctahedral (TOH) Au NCs enclosed by 24 high-index {441} facets, as effective cathode catalysts for Li-O2 batteries. All Au NCs can significantly reduce the charge potential and have high reversible capacities. In particular, TOH Au NC catalysts demonstrated the lowest charge-discharge overpotential and the highest capacity of ∼ 20 298 mA h g-1. The correlation between the different Au NC crystal planes and their electrochemical catalytic performances was revealed: high-index facets exhibit much higher catalytic activity than the low-index planes, as the high-index planes have a high surface energy because of their large density of atomic steps, ledges and kinks, which can provide a high density of reactive sites for catalytic reactions

Lovelock gravity from entropic force

In this paper, we first generalize the formulation of entropic gravity to (n+1)-dimensional spacetime. Then, we propose an entropic origin for Gauss-Bonnet gravity and more general Lovelock gravity in arbitrary dimensions. As a result, we are able to derive Newton's law of gravitation as well as the corresponding Friedmann equations in these gravity theories. This procedure naturally leads to a derivation of the higher dimensional gravitational coupling constant of Friedmann/Einstein equation which is in complete agreement with the results obtained by comparing the weak field limit of Einstein equation with Poisson equation in higher dimensions. Our study shows that the approach presented here is powerful enough to derive the gravitational field equations in any gravity theory. PACS: 04.20.Cv, 04.50.-h, 04.70.Dy.Comment: 10 pages, new versio

30 inch Roll-Based Production of High-Quality Graphene Films for Flexible Transparent Electrodes

We report that 30-inch scale multiple roll-to-roll transfer and wet chemical doping considerably enhance the electrical properties of the graphene films grown on roll-type Cu substrates by chemical vapor deposition. The resulting graphene films shows a sheet resistance as low as ~30 Ohm/sq at ~90 % transparency which is superior to commercial transparent electrodes such as indium tin oxides (ITO). The monolayer of graphene shows sheet resistances as low as ~125 Ohm/sq with 97.4% optical transmittance and half-integer quantum Hall effect, indicating the high-quality of these graphene films. As a practical application, we also fabricated a touch screen panel device based on the graphene transparent electrodes, showing extraordinary mechanical and electrical performances

Three-dimensional micromachining for microsystems by confined etchant layer technique

The micromachining of GaAs with three different truly three-dimensional (3D) molds were performed by the confined etchant layer technique (CELT). The etched patterns were found, approximately, to be the negative copy of the 3D molds. The general comparison of CELT with the existing micromachining techniques, such as two-dimensional (2D) projection lithography and electro-discharge machining, was made. The replication of the complex microstructures down to micrometer scale has been done by CELT in a single step. The photoresist layer, together with the procedures of exposure, developing and removal of resist, could be eliminated. The advantages of CELT over the existing lithography techniques and its potential applications are discussed briefly. It has been shown that CELT could be developed as a complementary technique to the existing micromachining techniques in fabricating microdevices for microsystems. (C) 2001 Elsevier Science Ltd. All rights reserved