Abstract
Building reliable real-time applications on top of commercial off-the-shelf (COTS) components is not a straightforward task. Thus, it is essential to provide a simple and transparent programming model, in order to abstract programmers from the low-level implementation details of distribution and replication. However, the recent trend for incorporating pre-emptive multitasking applications in reliable real-time systems inherently increases its complexity. It is therefore important to provide a transparent programming model, enabling preemptive multitasking applications to be implemented without resorting to simultaneously dealing with both system requirements and distribution and replication issues. The distributed embedded architecture using COTS components (DEAR-COTS) architecture has been previously proposed as an architecture to support real-time and reliable distributed computer-controlled systems (DCCS) using COTS components. Within the DEARCOTS architecture, the hard real-time subsystem provides a framework for the development of reliable real-time applications, which are the core of DCCS applications. This paper presents the proposed framework, and demonstrates how it can be used to support the transparent replication of software components.

Abstract

Abstract
The continuous improvement of Ethernet technologies is boosting the eagerness of extending their use to also cover factory-floor distributed real time applications. Indeed, it is remarkable the considerable amount of research work that has been devoted to the timing analysis of Ethernet-based technologies in the past few years. It happens, however, that the majority of those works are restricted to the analysis of sub-sets of the overall computing and communication system, thus without addressing timeliness in a holistic fashion. To this end, in this paper we address an approach, based on simulation, aiming at extracting temporal properties of Commercial-Off-The-Shelf (COTS) Ethernet-based factory-floor distributed systems. This framework is being applied to a specific COTS technology, Ethernet/IP. In this paper, we reason about the modeling and simulation of Ethernet/IP-based systems, and on the use of statistical analysis techniques to provide useful results on timeliness.

Abstract
In the past few years, a significant amount of work has been devoted to the timing analysis of Ethernet-based technologies. However, none of these address the problem of timeliness evaluation at a holistic level. This paper describes a research framework embracing this objective. It is advocated that, simulation models can be a powerful tool, not only for timeliness evaluation, but also to enable the introduction of less pessimistic assumptions in an analytical response time approach, which, most often, are afflicted with simplifications leading to pessimistic assumptions and, therefore. delusive results. To this end, we address a few inter-linked research topics with the purpose of setting a framework for developing tools suitable to extract temporal properties of Commercial-Off-The-Shelf (COTS) factory-floor communication systems.

Abstract
The use of an EPR within a hospital is essential in order to integrate and centralize patient healthcare information. With the introduction of this technology information security becomes an important issue, moreover when the EPR integrates several exam results and reports that need to be properly stored and managed. The Biostatistics and Medical Informatics Department in Porto's Faculty of Medicine is implementing a centralized Electronic Patient Record, the HSJ.ICU, to integrate several departments' information that comprises mainly electronic reports. The provision for the integrity of these documents is essential. Usually, the users of the system have blind trust in the information they access. The HSJ.ICU is implementing a process that digitally signs reports automatically, and therefore does not interfere with system's usability. It also provides for simple key management with the use of only one public key pair focusing protection in one single point. The digital signature provides real trust in the way it prevents and detects inconsistencies or errors that may affect information integrity. The approach presented in this paper will guarantee that when there is the need to access patient reports, whether now or in 20 years' time, those are still trustable and valid to be integrated within the EPR.

Abstract
Gemcitabine (2',2'-difluoro-2'-deoxycytidine, dFdC) is a very promising anticancer drug, already approved for clinical use in three therapeutic indications. It is metabolized intracellularly to 5'-diphosphate (dFdCDP), which is known to be a potent inhibitor of ribonucleotide reductase (RNR). Although several nucleotide analogs show in vitro capacity of RNR inactivation, none has shown the in vivo efficacy of dFdCDP. Accordingly, the experimental data suggests that its mechanism of inhibition is different from the other known RNR suicide inhibitors. Enzyme inhibition in the absence of reductive species leads to complete loss of the essential radical in subunit R2, and formation of a new nucleotide-based radical. Interestingly, however, the presence of the reductants does not prevent inhibition-the radical is not lost but the targeted subunit of RNR becomes R1, which is inactivated possibly by alkylation. We have conducted a theoretical study, which led us to the first proposal of a possible mechanism for RNR inhibition by dFdCDP in the absence of reductants. This mechanism turned out to be very similar to the natural substrate reduction pathway and only deviates from the natural course after the formation of the well-known disulphide bridge. This deviation is caused precisely by the F atom in the beta-face, only present in this inhibitor. The essential radical in R2 is lost, and so is the enzyme catalytic activity. The nucleotide-based radical that constitutes the end product of our mechanism has been suggested in the literature as a possible candidate for the one detected experimentally. In fact, all experimental data available has been reproduced by the theoretical calculations performed here. (C) 2004 Wiley Periodicals, Inc.