Voluntary disclosure of information in a setting in which endowment of information has productive value

This paper introduces a model capturing managers' disclosure policies in settings in which disclosure is rewarded by the financial market because disclosure implies that managers are endowed with information and endowment of information may potentially improve the firm's productive efficiency. It provides sufficient condition for a threshold disclosure equilibrium to obtain and compares disclosure policies in a setting in which endowment of information improves the firm's productive efficiency with disclosure policies in a setting in which endowment of information has no impact on the firm's productive efficiency. Managers' disclosure policies are shown to depend crucially on whether the endowment of information is exogenous or endogenous. When the endowment of information is exogenous, an increase in the usefulness of information in improving the firm's productive efficiency leads to a decrease in the disclosure threshold and hence an increase in the amount of information disclosed. In contrast, when the endowment of information is endogenous, an increase in the usefulness of information in improving the firm's productive efficiency has no effect on the disclosure threshold but leads to a decrease in the probability with which information is acquired and hence a decrease in the amount of information disclosed. As, in the threshold disclosure equilibrium, the net present value of information acquisition arising from any increase in production efficiency is negative, an increase in the usefulness of information in improving the firm's productive efficiency thus reduces the inefficiency caused by information acquisition. Copyright 2006 The Authors Journal compilation (c) 2006 Blackwell Publishing Ltd.

Deletion of the high-affinity cAMP phosphodiesterase encoded by PDE2 affects stress responses and virulence in Candida albicans

Previously, we have shown that PDE2 is required for hyphal development and cell wall integrity in Candida albicans. In the present study, we have investigated the effects of its deletion by genome-wide transcriptome profiling. Changes in expression levels of genes involved in metabolism, transcription, protein and nucleic acids synthesis, as well as stress responses, cell wall and membrane biogenesis, adherence and virulence have been observed. By comparing these changes with previously reported transcriptome profiles of pde2 Delta mutants of Saccharomyces cerevisiae, as well as cdc35 Delta, ras1 Delta and efg1 Delta mutants of C. albicans, conserved and species-specific cAMP-regulated genes have been identified. The genes whose transcription is altered upon deletion of PDE2 in C. albicans has also allowed us to predict that the pde2 Delta mutant would have a defective ability to adhere to, and invade host cells, and an impaired virulence as well as response to different stresses. Using appropriate assays, we have tested these predictions and compared the roles of the high- and low-affinity cAMP phosphodiesterases, Pde2p and Pde1p in stress, adhesion and virulence. We suggest that phosphodiesterases, and in particular the high-affinity cAMP phosphodiesterase encoded by PDE2, have real potential as targets for antifungal chemotherapy