Abstract
This paper proposes a virtual token-passing mechanism, which allows the coexistence of legacy industrial Ethernet devices with enhanced (real-time) devices in the same bus network. The VTPE mechanism allows the implementation of real-time (RT) applications upon legacy bus-based industrial networks, enforcing the adequate timing behavior of the supported applications. It enables the traffic separation between legacy Ethernet stations and enhanced (RT) stations. A set of experiments has been performed, which allowed to measure the message access delay and the token rotation time. The achieved results clearly demonstrate that the VTPE architecture enables the support of RT communication upon legacy bus-based industrial Ethernet networks, even when the communication medium is shared with uncontrolled traffic sources.

Abstract
Although there is an initial plan describing the rules to access an Electronic Medical Record (EMR) that is devised by implementers and software engineers, its access in practice is often different from what was envisaged. Healthcare professionals do not normally participate in the design of working tools, so they have to adapt their workflows around the systems in order to use them for their daily practice (being this one of the main reasons for health information systems failure); or they may circumvent the rules established for accessing the system because those rules are too cumbersome, time-consuming, or both. The objective of this paper is to study the usability of authentication and access control features in the healthcare environment with the use of qualitative methods. Usability studies using qualitative data collection and analysis can deeper explore people's behaviour when interacting with security technology and help understand better the context, workflows, needs and beliefs of users. This can facilitate in defining better security technology that is closer to the healthcare practice.

Abstract
Electrical Power Quality represents a challenging as much as attracting research topic nowadays, with consequences to all economic areas. Here, we studied the alternatives for reactive compensation in a residential low-voltage distribution grid using the Alternative Transient Program (ATP-EMTP). We developed a simulation model based on the results obtained from field measurements in a low voltage residential distribution grid with non-linear loads. We employed capacitors in different strategic places throughout the grid and changed their configurations, aiming to evaluate the technical viability of the application of reactive compensation. In this way, we investigated a methodology for the optimization of reactive compensation in secondary distribution grids, based on different solutions, in order to improve the voltage profile throughout the grid, as well as the technical losses that occur in a grid of this type. Next, we compared the simulated results with the field measurements. This analysis revealed that both approaches produced similar results, validating the simulation model. We therefore conclude that this model effectively reproduces the real linear and non-linear loads of the residential distribution grid and is suitable to be used in future studies. © 2011 IEEE.

Abstract
Access control defines what users can perform within a system. It is usually defined by software engineers and end users are seldom asked for cooperation. The main objective of this paper is to gather the necessary knowledge from the end users of an Electronic Medical Record (EMR) regarding access control and, with their collaboration, define a list of usable access control rules and access control model, which are closer to user needs and workflows. Access control standards in healthcare were also analyzed. Afterwards, focus groups were applied to health professionals and several access control rules were extracted from the analysis of all the information that was gathered. The Break The Glass - Role Based Access Control model (BTG-RBAC) was created and includes the generated access control rules, which are closer to users' workflows and needs and can, therefore, improve EMR's usability while reducing some barriers for its effective integration.

Abstract
Phosphoprotein phosphatases (PPPs) constitute one of three otherwise unrelated families of enzymes that specialize in removing the phosphate group from phosphorylated serine and threonine residues. The involvement of PPP enzymes in the regulation of processes such as gene expression, DNA replication, morphogenesis, synaptic transmission, glycogen metabolism, and apoptosis has underscored their potential as targets for the treatment of a variety of conditions such as cancer, diabetes, or Alzheimer''s disease. Interestingly, PPP enzymes also constitute the physiological target of multiple naturally occurring toxins, including microcystins from cyanobacteria and cantharidin from beetles. This review is devoted to the PPP family of enzymes--with a focus on the human PPPs--and the naturally occurring toxins that are known to potently impair their activity. The interaction of the toxins with the enzymes is evaluated in atomic detail to obtain insight on two complementary aspects: (1) which specific structural differences within the similarly folded catalytic core of the PPP enzymes explain their diverse sensitivities to toxin inhibition and (2) which structural features presented by the various toxins account for the differential inhibitory potency towards each PPP. These analyses take advantage of numerous site-directed mutagenesis studies, structure-activity evaluations, and recent crystallographic structures of PPPs bound to different toxins.

Abstract