Agency Contracts, Noncommitment Timing Strategies, and Real Options

Given an owner's noncommitment timing strategy and a manager's hidden action, we consider how the optimal compensation contract for the manager is designed and how the corresponding timing decisions to launch the project and replace the manager are determined. Using a real options approach, we show that in comparison with the firstbest case, the higher (lower)-quality project is launched later (at the same time as the first-best case), whereas the incumbent manager is replaced earlier. We also indicate that compared with the case of the owner’s commitment timing strategy and the manager's hidden action, the higher (lower)-quality project is launched later (at the same time as the first-best case), whereas the incumbent manager is (is not necessarily) replaced later if the hidden-action problem is severe enough (is not severe enough). Unlike the folklore result of the standard moral hazard model, severance pay may serve to minimize the compensation for the manager's loss of his option value caused by loss of corporate control by committing the owner to delaying replacement of the manager if the hidden-action problem is not too severe.CEO turnover, executive compensation, noncommitment, real options, severance pay.

VHL-Associated Optic Nerve Hemangioblastoma Treated with Stereotactic Radiosurgery

Central nervous system hemangioblastomas are generally restricted to the cerebellum, spinal cord, and brainstem. Supratentorial hemangioblastomas are uncommon, and optic nerve hemangioblastomas are extremely rare, with fewer than 25 reports including this case. In this report, we present the case of a 36-year-old woman with von Hippel–Lindau (VHL) disease who presented with progressive diminution of vision in the left eye due to a retrobulbar optic nerve hemangioblastoma. The patient had a history of cerebellar/spinal hemangioblastomas and pancreatic cysts, and her father and brother were patients with VHL disease. Gadol-inium-enhanced magnetic resonance imaging showed intraorbital retrobulbar–enhanced mass on the left optic nerve. The optic nerve hemangioblastoma was treated with fractionated stereotactic radiosurgery using Novalis. Eighteen months after the stereotactic radiosurgery, the tumor volume decreased although the patient lost vision. This report presents an extremely rare case of optic nerve hemangioblastoma, which is the first case treated with stereotactic radiosurgery

Activation of the chicken Ig-β locus by the collaboration of scattered regulatory regions through changes in chromatin structure

A total of 10 B-lymphocyte-specific DNase I hypersensitive sites located in the chicken Ig-β locus were divided into four regions and combinations of deletions of these regions were carried out. A decrease in transcription of the Ig-β gene to <3% was demonstrated in cells with deletions in all four regions. The Ig-β chromatin was resistant to DNase I digestion in these cells. Thus, the collaboration is shown to convert the Ig-β chromatin from the condensed state to a relaxed state. H3 and H4 acetylation decreased to <8% but H3K4 hypermethylation was observed at the Ig-β promoter and exon 3. The collaboration of four regions had virtually no effect on CG hypomethylation in the region upstream the transcriptional start site. Accordingly, neither the DNase I general sensitive state in the Ig-β chromatin nor hyperacetylation of H3 and H4 histones in the promoter proximal region causes H3K4 di-methylation or CG hypomethylation in the promoter. From these analyses, a chromatin situation was found in which both an active state, such as enhanced H3K4 methylation, or CG hypomethylation, and an inactive state, such as DNase I resistance in the Ig-β chromatin or hypoacetylation of H3 and H4 histones in the Ig-β locus, coexist