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Photoactive films derived from nanostructured samples of metal-free, intermediate band gap semiconductor graphitic carbon nitride (ns-g-C3N4) have been synthesized and characterized for their particle properties and antimicrobial activity. Physical characterization reveals that these materials are composed of discrete nanoparticles whose dimensions range from 200 nm to 700 nm. Investigation of the photochemical reactivity of ns-g-C3N4 using coumarin-3-carboxylic acid (3-CCA) indicates that this material produces reactive oxygen species (ROS) under visible radiation. When irradiated with 0.31 J visible light, ns-g-C3N4-based materials reduced the viability of both Gram-negative Escherichia coli O157:H7 and Gram-positive Staphylococcus aureus by approximately 50%. Nearly complete inactivation of both strains of microorganisms was achieved upon administration of a 0.62 J dose of visible radiation. Importantly, no biocidal activity was observed for non-irradiated samples, indicating that the g-C3N4-derived films are not inherently toxic in the absence of visible light. The results of this study suggest that materials and, by extention, films and coatings derived from g-C3N4 may present a novel route for controlling pathogenic microorganisms on surfaces in the environment, and could be useful in reducing incidents of hospital-acquired infections.

The Faculty of Accident and Emergency Medicine was inaugurated on 2 November 1993. The new council decided that it would like a logo or badge to signify its identity and to adorn such items as headed notepaper and the president's badge of office. As registrar I was instructed to approach the College of Arms for letters-patent granting the faculty its own coat of arms. Because of the multidisciplinary nature of accident and emergency medicine, the faculty is an intercollegiate one based on six royal colleges. The faculty has flourished, it has a steadily increasing membership, and the faculty board's examination committee holds regular examinations for fellowship of the faculty twice a year. The first step was to approach the College of Arms in London and the duty herald, who in our case was William Hunt, Portcullis Pursuivant of Arms. He led me through the detailed process of acquiring our armorial bearings. We submitted the articles of constitution of the faculty to Portcullis, who submitted them to the Kings of Arms. The faculty was then given permission to petition the Earl Marshal for armorial bearings. Portcullis had made it clear that the smaller the committee designing the coat of arms the better. He favoured a committee of one. In the event we formed a small subcommittee of three. Figure 1 shows the principal elements of an achievement of arms, in this case those of the Worshipful …

The increasing need for unattended sensor networks drives individual sensor development, signal processing for network management, and communication technology. The application space is becoming more complex, with requirements for sensor networks in force protection; surveillance of large expanses of rugged terrain; and monitoring complex urban areas. Individual sensors exhibit excellent performance and include a wide variety of sensing modes, such as acoustic, electro-optical imaging, seismic, and radio frequency devices. These sensors continue to shrink with packaging, while applications continue to demand more of the sensor technology. Although single imaging arrays, which are available in spectral bands from the visible through the infrared, can be integrated into packages size as small as a cubic inch, the information from a single sensor is not sufficient to meet requirements for day/night, all-weather operation. This has driven the need for integration of multiple sensors into the compact packages intended for an individual sensor. A major step toward addressing the need for more effective sensor technology for unattended sensor networks is being taken through development of Vertically Integrated Sensor Array (VISA) technology. This technology, currently being developed for imaging sensors, builds multiple layers of signal processing at each pixel in the sensor array. Processing power is dramatically increased, allowing the integration of multiple sensors in small compact packages. This paper reviews the VISA approach to imaging sensors and describes applications for unattended sensors.

The Working Mathematics Group, a voluntary body which works on a shoestring budget mostly raised its own efforts, has a proud record of achievement. Yet it looks like moving into a crisis condition towards the end of this year for lack of financial support. While this is happening the MSC is proposing to invade the field of preparing open learning materials by some sort of bureaucratic system to be paid for out of public funds. In this journal, in our Phoenix Series, we argue that what is required is the reverse of this situation: we need to harness local effort, and voluntary effort, especially when it happens also to be expert effort, in the service of the community — a feature which WMG illustrates to perfection — and move away from organising everything from the centre by highly‐paid career bureaucrats in the manner of the MSC and the Ministries. Now read the inside story from the point of view of the WMG. One lesson is that the disbursement of funds from the public purse to the various agents working to restore the country's prosperity is not really co‐ordinated by any part of the system: one Ministry seems not to know what the others are doing in areas of mutual interest and responsibility. Another lesson is that surely voluntary bodies, with their economical way of working, their ability to address themselves to real problems and their capacity to draw on a corps of dedicated workers giving their services free, should be protected from being driven out of business by the civil service empire builders. (Editor)