1,072 research outputs found
Does managerial ability affect corporate financial constraints? Evidence from China
We study the effect of managerial ability on financial constraints
of Chinese listed companies. Our results indicate a negative relationship between managerial ability and corporate financial constraints. Further analyses show that managerial ability helps
alleviate financial constraints probably through lowering information asymmetry, reducing agency conflicts and enhancing corporate profitability. In addition, we find evidence that private firms
suffer from more severe financial constraints than state- and foreign-owned firms, and the effect of managerial ability in alleviating financial constraints is more pronounced for private firms.
Overall, our findings help understand the role and highlight the
importance of managerial ability in alleviating financial
constraints
Managerial ability, financial performance and goodwill impairment: A moderated mediation analysis
This paper examines whether and how managerial ability affects the likelihood of goodwill impairment of Chinese publicly listed companies over the period 2007-2017. We document a negative relationship between goodwill impairment and managerial ability, and uncover the mediation effect of corporate financial performance. Moreover, we find that the mediation effect is moderated by firms’ earnings smoothing motivation and state ownership. The results suggest that when a company has the motivation to smooth earnings or is owned by the government, higher managerial ability of the company does not necessarily reduce the likelihood of goodwill impairment. The findings have important implications for investors and regulators
Full Hydrodynamic Model of Nonlinear Electromagnetic Response in Metallic Metamaterials
Applications of metallic metamaterials have generated significant interest in
recent years. Electromagnetic behavior of metamaterials in the optical range is
usually characterized by a local-linear response. In this article, we develop a
finite-difference time-domain (FDTD) solution of the hydrodynamic model that
describes a free electron gas in metals. Extending beyond the local-linear
response, the hydrodynamic model enables numerical investigation of nonlocal
and nonlinear interactions between electromagnetic waves and metallic
metamaterials. By explicitly imposing the current continuity constraint, the
proposed model is solved in a self-consistent manner. Charge, energy and
angular momentum conservation laws of high-order harmonic generation have been
demonstrated for the first time by the Maxwell-hydrodynamic FDTD model. The
model yields nonlinear optical responses for complex metallic metamaterials
irradiated by a variety of waveforms. Consequently, the multiphysics model
opens up unique opportunities for characterizing and designing nonlinear
nanodevices.Comment: 11 pages, 14 figure
Caffeine-Induced Global Reductions in Resting-State BOLD Connectivity Reflect Widespread Decreases in MEG Connectivity.
In resting-state functional magnetic resonance imaging (fMRI), the temporal correlation between spontaneous fluctuations of the blood oxygenation level dependent (BOLD) signal from different brain regions is used to assess functional connectivity. However, because the BOLD signal is an indirect measure of neuronal activity, its complex hemodynamic nature can complicate the interpretation of differences in connectivity that are observed across conditions or subjects. For example, prior studies have shown that caffeine leads to widespread reductions in BOLD connectivity but were not able to determine if neural or vascular factors were primarily responsible for the observed decrease. In this study, we used source-localized magnetoencephalography (MEG) in conjunction with fMRI to further examine the origins of the caffeine-induced changes in BOLD connectivity. We observed widespread and significant (p < 0.01) reductions in both MEG and fMRI connectivity measures, suggesting that decreases in the connectivity of resting-state neuro-electric power fluctuations were primarily responsible for the observed BOLD connectivity changes. The MEG connectivity decreases were most pronounced in the beta band. By demonstrating the similarity in MEG and fMRI based connectivity changes, these results provide evidence for the neural basis of resting-state fMRI networks and further support the potential of MEG as a tool to characterize resting-state connectivity
5,5′-(p-PhenylÂene)di-1H-tetraÂzole
Crystals of the title organic compound, C8H6N8, were generated in situ through the [2 + 3]-cycloÂaddition reaction involving the precursor 1,4-dicyanoÂbenzene and azide in water with Zn2+ as Lewis acid. The asymmetric unit consists of one half-molÂecule, and a twofold axis of symmetry passes through the centre of the benzene ring. There is an interÂmolecular N—H⋯N hydrogen bond. The molÂecules are assembled into a three-dimensional supraÂmolecular framework by π–π stacking interÂactions, with a perpendicular distance of 3.256 Å [centroid–centroid = 3.9731 (8) Å] between two tetraÂzole ring planes, and 3.382 Å between the benzÂene ring and tetraÂzole ring planes [centroid–centroid = 3.5010 (9) Å]
R\'{e}nyi Divergence Deep Mutual Learning
This paper revisits Deep Mutual Learning (DML), a simple yet effective
computing paradigm. We propose using R\'{e}nyi divergence instead of the KL
divergence, which is more flexible and tunable, to improve vanilla DML. This
modification is able to consistently improve performance over vanilla DML with
limited additional complexity. The convergence properties of the proposed
paradigm are analyzed theoretically, and Stochastic Gradient Descent with a
constant learning rate is shown to converge with -bias in the
worst case scenario for nonconvex optimization tasks. That is, learning will
reach nearby local optima but continue searching within a bounded scope, which
may help mitigate overfitting. Finally, our extensive empirical results
demonstrate the advantage of combining DML and R\'{e}nyi divergence, which
further improves generalized models
Case report: Neural timing deficits prevalent in developmental disorders, aging, and concussions remediated rapidly by movement discrimination exercises
BackgroundThe substantial evidence that neural timing deficits are prevalent in developmental disorders, aging, and concussions resulting from a Traumatic Brain Injury (TBI) is presented.ObjectiveWhen these timing deficits are remediated using low-level movement-discrimination training, then high-level cognitive skills, including reading, attention, processing speed, problem solving, and working memory improve rapidly and effectively.MethodsIn addition to the substantial evidence published previously, new evidence based on a neural correlate, MagnetoEncephalography physiological recordings, on an adult dyslexic, and neuropsychological tests on this dyslexic subject and an older adult were measured before and after 8-weeks of contrast sensitivity-based left–right movement-discrimination exercises were completed.ResultsThe neuropsychological tests found large improvements in reading, selective and sustained attention, processing speed, working memory, and problem-solving skills, never before found after such a short period of training. Moreover, these improvements were found 4 years later for older adult. Substantial MEG signal increases in visual Motion, Attention, and Memory/Executive Control Networks were observed following training on contrast sensitivity-based left–right movement-discrimination. Improving the function of magnocells using figure/ground movement-discrimination at both low and high levels in dorsal stream: (1) improved both feedforward and feedback pathways to modulate attention by enhancing coupled theta/gamma and alpha/gamma oscillations, (2) is adaptive, and (3) incorporated cycles of feedback and reward at multiple levels.ConclusionWhat emerges from multiple studies is the essential role of timing deficits in the dorsal stream that are prevalent in developmental disorders like dyslexia, in aging, and following a TBI. Training visual dorsal stream function at low levels significantly improved high-level cognitive functions, including processing speed, selective and sustained attention, both auditory and visual working memory, problem solving, and reading fluency. A paradigm shift for treating cognitive impairments in developmental disorders, aging, and concussions is crucial. Remediating the neural timing deficits of low-level dorsal pathways, thereby improving both feedforward and feedback pathways, before cognitive exercises to improve specific cognitive skills provides the most rapid and effective methods to improve cognitive skills. Moreover, this adaptive training with substantial feedback shows cognitive transfer to tasks not trained on, significantly improving a person’s quality of life rapidly and effectively
Genetic targeting of arginase-ii in mouse prevents renal oxidative stress and inflammation in diet-induced obesity
Obesity is associated with development and progression of chronic kidney disease (CKD). Recent evidence demonstrates that enhanced levels of the L- arginine:ureahydrolase, including the two isoenzymes arginase-I (Arg-I) and arginase- II (Arg-II) in vascular endothelial cells promote uncoupling of endothelial nitric oxide synthase (eNOS), leading to increased superoxide radical anion and decreased NO production thereby endothelial dysfunction. Arg-II but not Arg-I is abundantly expressed in kidney and the role of Arg-II in CKD is uncertain and controversial. We aimed to investigate the role of Arg-II in renal damage associated with diet-induced obesity mouse model. Wild type (WT) C57BL/6 mice and mice deficient in Arg-II gene (Arg-II−/−) were fed with either a normal chow (NC) or a high-fat-diet (HFD) for 14 weeks (starting at the age of 7 weeks) to induce obesity. In WT mice, HFD feeding caused frequent renal lipid accumulation, enhancement of renal reactive oxygen species (ROS) levels which could be attenuated by a NOS inhibitor, suggesting uncoupling of NOS in kidney. HFD feeding also significantly augmented renal Arg-II expression and activity. All the alterations in the kidney under HFD feeding were reduced in Arg-II−/− mice. Moreover, mesangial expansion as analyzed by Periodic Acid Schiff (PAS) staining and renal expression of vascular adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) in HFD-fed WT mouse assessed by immunoblotting were reduced in the HFD-fed Arg- II−/− mice, although there was no significant difference in body weight and renal weight/body weight ratio between the WT and Arg-II−/− mice. Thus, Arg-II expression/activity is enhanced in kidney of diet-induced obesity mice. Genetic targeting of Arg-II prevents renal damage associated with obesity, suggesting an important role of Arg-II in obesity-associated renal disease development
- …