Conceptualizing the key features of cyber-physical systems in a multi-layered representation for safety and security analysis

Many safety‐related systems are evolving into cyber‐physical systems (CPSs), integrating information technologies in their control architectures and modifying the interactions among automation and human operators. Particularly, a promising potential exists for enhanced efficiency and safety in applications such as autonomous transportation systems, control systems in critical infrastructures, smart manufacturing and process plants, robotics, and smart medical devices, among others. However, the modern features of CPSs are ambiguous for system designers and risk analysts, especially considering the role of humans and the interactions between safety and security. The sources of safety risks are not restricted to accidental failures and errors anymore. Indeed, cybersecurity attacks can now cascade into safety risks leading to physical harm to the system and its environment. These new challenges demand system engineers and risk analysts to understand the security vulnerabilities existing in CPS features and their dependencies with physical processes. Therefore, this paper (a) examines the key features of CPSs and their relation with other system types; (b) defines the dependencies between levels of automation and human roles in CPSs from a systems engineering perspective; and (c) applies systems thinking to describe a multi‐layered diagrammatic representation of CPSs for combined safety and security risk analysis, demonstrating an application in the maritime sector to analyze an autonomous surface vehicle

Chronic administration of androgens with actions at estrogen receptor beta have anti-anxiety and cognitive-enhancing effects in male rats

Androgen levels decline with aging. Some androgens may exert anti-anxiety and cognitive-enhancing effects; however, determining which androgens have anxiolytic-like and/or mnemonic effects is of interest given the different mechanisms that may underlie some of their effects. For example, the 5α-reduced metabolite of testosterone (T), dihydrotesterone, can be further converted to 5α-androstane,17β-diol-3α-diol (3α-diol) and 5α-androstane,17β-diol-3β-diol (3β-diol), both of which bind with high affinity to the beta isomer of the intracellular estrogen receptor beta (ERβ). However, androsterone, another metabolite of T, does not bind well to ERβ. To investigate the effects of T metabolites, male rats were subjected to gonadectomy then implanted with silastic capsules of 3α-diol, 3β-diol, androsterone, or oil control. After recovery, the rats were tested in elevated plus maze (EPM), light/dark transition (LD), and Morris water maze (MWM). 3α-diol both decreased anxiety-like behavior in the EPM and LD, and increased cognition in MWM, while 3β-diol improved cognition in MWM, but had no effects on anxiety behavior, compared to vehicle or androsterone. These data suggest that the actions of 3α-diol and 3β-diol at ERβ may be responsible for some of testosterone’s anti-anxiety and cognitive-enhancing effects