This is not a survey article. Rather it is a personal statement written for a lifelong friend and collaborator. Still it is an ambition of this article to trace some of the key moments of our development in the past 40 years. In doing so perhaps some evidence has arisen which otherwise seems to be obscured by the hectic day-to-day academic life. Thus the title. Supported by ITI and DIMATIA of C...

The quantum principles of superposition and entanglement have led to a recasting of the foundations of information and computation theory, and are especially helpful in understanding the nature of privacy. The most private information, exemplified by a quantum eraser experiment, is best regarded as existing only conditionally and temporarily—after the experiment is over no trace remains. Less p...

A class of nonlinear difference systems is considered in this paper. By exploring the relationship between this system and a correspondent first-order difference system, some permanence results are obtained.

Ownership types support information hiding by providing object-based encapsulation. However the static restrictions they impose on object accessibility can limit the expressiveness of ownership types. In order to deal with real applications, it is sometimes necessary to admit mechanisms for dynamically exposing otherwise encapsulated information. The need for policies and mechanisms to control ...

Results 69 pts (47 years, male 69%, SAPS II 33, mechanical ventilation 92%) developed 77 episodes (M 44, V 32). Neurosurgical diseases were trauma (39%), meningeal hemorrhage (20%), intracerebral hemorrhage (17%), intracranial tumor (12%). Cerebrospinal fluid leakage was present in 25%, ventriculostomy in 35% (catheter permanence 6.2 days), subdural catheter in 30% (catheter permanence 4.2 days...