The changing role of the supervisory board chairman: the case of the Netherlands (1997-2007)

Over the last ten years, the corporate governance context in most Western countries has changed as a result of irregularities, increased regulation, heightened societal expectations and shareholder activism. This paper examines the impact of the changing context on the role of chairmen of supervisory boards in the Netherlands. Based on a combination of thirty semi-structured interviews with board members of leading Dutch corporations and secondary data on the position of supervisory board chairmen at the top-100 listed firms in the Netherlands, the study reveals that board chairmen have become increasingly involved in both their control and service roles. While the demographics (i.e., age, tenure, gender and nationality) of chairmen have hardly changed over the last decade, chairmen are spending considerably more time on boards and committees, have reduced the number of board interlocks and have become more active on the forefront of the corporate governance discussion. The paper highlights several implications for scholars and practitioners.

A plasmonic 'ac Wheatstone bridge' circuit for high-sensitivity phase measurement and single-molecule detection

In this paper, a plasmonic “ac Wheatstone bridge” circuit is proposed and theoretically modeled for the first time. The bridge circuit consists of three metallic nanoparticles, shaped as rectangular prisms, with two nanoparticles acting as parallel arms of a resonant circuit and the third bridging nanoparticle acting as an optical antenna providing an output signal. Polarized light excites localized surface plasmon resonances in the two arms of the circuit, which generate an optical signal dependent on the phase-sensitive excitations of surface plasmons in the antenna. The circuit is analyzed using a plasmonic coupling theory and numerical simulations. The analyses show that the plasmonic circuit is sensitive to phase shifts between the arms of the bridge and has the potential to detect the presence of single molecules.

SwarmPS: Rapid, semi-automated single particle selection software

Single particle analysis (SPA) coupled with high-resolution electron cryo-microscopy is emerging as a powerful technique for the structure determination of membrane protein complexes and soluble macromolecular assemblies. Current estimates suggest that ∼104–105 particle projections are required to attain a 3 Å resolution 3D reconstruction (symmetry dependent). Selecting this number of molecular projections differing in size, shape and symmetry is a rate-limiting step for the automation of 3D image reconstruction. Here, we present SwarmPS, a feature rich GUI based software package to manage large scale, semi-automated particle picking projects. The software provides cross-correlation and edge-detection algorithms. Algorithm-specific parameters are transparently and automatically determined through user interaction with the image, rather than by trial and error. Other features include multiple image handling (∼102), local and global particle selection options, interactive image freezing, automatic particle centering, and full manual override to correct false positives and negatives. SwarmPS is user friendly, flexible, extensible, fast, and capable of exporting boxed out projection images, or particle coordinates, compatible with downstream image processing suites.