University of Arkansas

About: University of Arkansas is a education organization based out in Fayetteville, Arkansas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 17225 authors who have published 33329 publications receiving 941102 citations. The organization is also known as: Arkansas & UA.

Environmental Effects on Photoluminescence of Highly Luminescent CdSe and CdSe/ZnS Core/Shell Nanocrystals in Polymer Thin Films

Abstract: We report our systematic studies of the environmental effects on the photoluminescence (PL) from colloidal CdSe nanocrystals (NCs) embedded in polymer thin films. The highly luminescent bare-core CdSe NCs were significantly more robust than the core/shell CdSe/ZnS NCs against photoannealing under inert environments, while the core/shell NCs are more resistant to photooxidation. For the case of bare-core NCs, we show the importance of the initial photoactivation as the proper treatment for subsequent studies, a step that is basically irrelevant in the case of core/shell NCs. By measuring the PL wavelength shift, PL line width, and PL intensity, we investigated the dynamic changes of the emission properties of these NCs under different environments, including argon, oxygen, air, water vapor, and wet oxygen, and under different excitation conductions to reveal the photoinduced nature of the interactions between the nanocrystal surface and the environment. Mechanisms related to photoactivation, photooxidation...

Earnings Management, Litigation Risk, and Asymmetric Audit Fee Responses

Abstract: This study empirically examines the asymmetric association between the auditor's assessment of litigation risk and earnings management, using publicly available fee data. Following the experimental work of Barron et al. (2001), we document decreases (increases) in audit fees with clients' risk of managing earnings downward (upward). We also find that the positive fee association is greater for clients facing greater litigation risk resulting from negative earnings surprises. We test our hypotheses with a sample of 429 public, non-regulated, Big 5-audited companies, using fee data for the year 2000. We interpret these findings as consistent with auditors' assessments of decreased (increased) litigation risk imposed by conservative (aggressive) clients. This interpretation is consistent with the positive relation between accruals and auditor litigation (Heninger 2001; Lys and Watts 1994), the relation between restatement and larger accruals (Richardson et. al 2003) and the relation between restatements and auditor litigation (Palmrose and Scholz 2000).