Molecular photovoltaics and the photoactivation of mammalian cells

Photosynthetic reaction centers are integral plant membrane protein complexes and molecular photovoltaic structures. We report here that addition of Photosystem I (PSI)-proteoliposomes to retinoblastoma cells imparts photosensitivity to these mammalian cells, as demonstrated by light-induced movement of calcium ions. Control experiments with liposomes lacking PSI demonstrated no photosensitivity. The data demonstrate that PSI, a nanoscale molecular photovoltaic structure extracted from plants, can impart a photoresponse to mammalian cells in vitro.     

Rethinking security properties, threat models, and the design space in sensor networks: A case study in SCADA systems

In recent years we have witnessed the emergence and establishment of research in sensor network security. The majority of the literature has focused on discovering numerous vulnerabilities and attacks against sensor networks, along with suggestions for corresponding countermeasures. However, there has been little guidance for understanding the holistic nature of sensor network security for practical deployments. In this paper, we discuss these concerns and propose a taxonomy composed of the security properties of the sensor network, the threat model, and the security design space. In particular, we try to understand the application-layer goals of a sensor network, and provide a guide to research challenges that need to be addressed in order to prioritize our defenses against threats to application-layer goals.