Dynamic modulation of modal coupling in microelectromechanical gyroscopic ring resonators

Abstract: Understanding and controlling modal coupling in micro/nanomechanical devices is integral to the design of high-accuracy timing references and inertial sensors. However, insight into specific physical mechanisms underlying modal coupling, and the ability to tune such interactions is limited. Here, we demonstrate that tuneable mode coupling can be achieved in capacitive microelectromechanical devices with dynamic electrostatic fields enabling strong coupling between otherwise uncoupled modes. A vacuum-sealed microelectromechanical silicon ring resonator is employed in this work, with relevance to the gyroscopic lateral modes of vibration. It is shown that a parametric pumping scheme can be implemented through capacitive electrodes surrounding the device that allows for the mode coupling strength to be dynamically tuned, as well as allowing greater flexibility in the control of the coupling stiffness. Electrostatic pump based sideband coupling is demonstrated, and compared to conventional strain-mediated sideband operations. Electrostatic coupling is shown to be very efficient, enabling strong, tunable dynamical coupling

Design of a partial peptide mimetic of anginex with antiangiogenic and anticancer activity

Based on structure-activity relationships of the angiostatic ß-sheet-forming peptide anginex, we have designed a mimetic, 6DBF7, which inhibits angiogenesis and tumor growth in mice. 6DBF7 is composed of a ß-sheet-inducing dibenzofuran (DBF)-turn mimetic and two short key amino acid sequences from anginex. This novel antiangiogenic molecule is more effective in vivo than parent anginex. In a mouse xenograft model for ovarian carcinoma, 6DBF7 is observed to reduce tumor growth by up to 80%. It is suggested that the activity is based on antiangiogenesis, because in vitro tube formation is inhibited, and because treatment of tumor-bearing mice led to a significant reduction in microvessel density within the tumor. This partial peptide mimetic is the first endothelial cell-specific molecule designed as a substitute for an angiostatic inhibitory peptide

Design of a partial peptide mimetic of anginex with antiangiogenic and anticancer activity

Based on structure-activity relationships of the angiostatic ß-sheet-forming peptide anginex, we have designed a mimetic, 6DBF7, which inhibits angiogenesis and tumor growth in mice. 6DBF7 is composed of a ß-sheet-inducing dibenzofuran (DBF)-turn mimetic and two short key amino acid sequences from anginex. This novel antiangiogenic molecule is more effective in vivo than parent anginex. In a mouse xenograft model for ovarian carcinoma, 6DBF7 is observed to reduce tumor growth by up to 80%. It is suggested that the activity is based on antiangiogenesis, because in vitro tube formation is inhibited, and because treatment of tumor-bearing mice led to a significant reduction in microvessel density within the tumor. This partial peptide mimetic is the first endothelial cell-specific molecule designed as a substitute for an angiostatic inhibitory peptide

Critical Discourse Analysis: Definition, Approaches, Relation to Pragmatics, Critique, and Trends

This chapter introduces the transdisciplinary research movement of critical discourse analysis (CDA) beginning with its definition and recent examples of CDA work. In addition, approaches to CDA such as the dialectical relational (Fairclough), sociocognitive (van Dijk), discourse historical (Wodak), social actors (van Leeuwen), and the Foucauldian dispositive analysis (Jager and Maier) are outlined, as well as the complex relation of CDA to pragmatics. Next, the chapter provides a brief mention of the extensive critique of CDA, the creation of critical discourse studies (CDS), and new trends in CDA, including positive discourse analysis (PDA), CDA with multimodality, CDA and cognitive linguistics, critical applied linguistics, and other areas (rhetoric, education, anthropology/ethnography, sociolinguistics, culture, feminism/gender, and corpus studies). It ends with new directions aiming towards social action for social justice