3C-SiC — From Electronic to MEMS Devices

Since decades, silicon carbide (SiC) has been avowed as an interesting material for high-power and high-temperature applications because of its significant properties including its wide bandgap energy and high temperature stability. SiC is also professed as an ideal candidate for microsystem applications due to its excellent mechanical properties and chemical inertia, making it suitable for harsh environments. Among the 250 different SiC polytypes, only 4H, 6H and 3C-SiC are commercially available. The cubic structure, 3C-SiC, is the only one that can be grown on cheap silicon substrates. Hence, 3C-SiC is more interesting than any other polytype for reducing fabrication costs and increasing wafer diameter. This huge property has been evidenced for more than 30 years using chemical vapor deposition. Despite this key achievement and the growing interest for silicon carbide, no 3C-SiC-based devices can be found on the market whereas 4H-SiC-based devices are more and more largely commercialized. Even so, important headways have been reached for electrical and microelectromechanical systems (MEMS) applications. Therefore, the purpose of this chapter is to address concerns related to electronic applications and MEMS fabrication of 3C-SiC-based devices, trying to give a broad overview on specific issues and challenging solutions

ODAS: Open embeddeD Audition System

Artificial audition aims at providing hearing capabilities to machines, computers and robots. Existing frameworks in robot audition offer interesting sound source localization, tracking and separation performance, but involve a significant amount of computations that limit their use on robots with embedded computing capabilities. This paper presents ODAS, the Open embeddeD Audition System framework, which includes strategies to reduce the computational load and perform robot audition tasks on low-cost embedded computing systems. It presents key features of ODAS, along with cases illustrating its uses in different robots and artificial audition applications

Epstein-Barr Virus Interferes with the Amplification of IFNα Secretion by Activating Suppressor of Cytokine Signaling 3 in Primary Human Monocytes

Epstein-Barr virus is recognized to cause lymphoproliferative disorders and is also associated with cancer. Evidence suggests that monocytes are likely to be involved in EBV pathogenesis, especially due to a number of cellular functions altered in EBV-infected monocytes, a process that may affect efficient host defense. Because type I interferons (IFNs) are crucial mediators of host defense against viruses, we investigated the effect of EBV infection on the IFNalpha pathway in primary human monocytes.Infection of monocytes with EBV induced IFNalpha secretion but inhibited the positive feedback loop for the amplification of IFNalpha. We showed that EBV infection induced the expression of suppressor of cytokine signaling 3 (SOCS3) and, to a lesser extent, SOCS1, two proteins known to interfere with the amplification of IFNalpha secretion mediated by the JAK/STAT signal transduction pathway. EBV infection correlated with a blockage in the activation of JAK/STAT pathway members and affected the level of phosphorylated IFN regulatory factor 7 (IRF7). Depletion of SOCS3, but not SOCS1, by small interfering RNA (siRNA) abrogated the inhibitory effect of EBV on JAK/STAT pathway activation and significantly restored IFNalpha secretion. Finally, transfection of monocytes with the viral protein Zta caused the upregulation of SOCS3, an event that could not be recapitulated with mutated Zta.We propose that EBV protein Zta activates SOCS3 protein as an immune escape mechanism that both suppresses optimal IFNalpha secretion by human monocytes and favors a state of type I IFN irresponsiveness in these cells. This immunomodulatory effect is important to better understand the aspects of the immune response to EBV